1 


m 

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UNIVERSITY  OF  CALIFORNIA 
AT   LOS  ANGELES 


e  RALPH  D.  REED  LIBRARY 


DEPARTMENT  OF  GEOLOGY 

UNIVERSITY  of  CALIFORNIA 

LOS  ANGELES,  CALIF. I 


^ift  of  Oil  Companies  of  Southern  Cali- 
fornia, Alumni  and  Faculty  of  Geology  Depart- 
ment and  University  Library. 

1940 


A  GUIDE 


SCIENTIFIC  EXAMINATION  OF  SOILS: 


COMPRISING 


SELECT  METHODS  OF  MECHANICAL  AND  CHEMICAL  ANALYSIS 
AND  PHYSICAL  INVESTIGATION. 


TRANSLATED  FROM  THE  GERMAN  OF 

DR.   FELIX    WAHNSCHAFFE. 

WITH   ADDITIONS   BY 

WILLIAM  T.  BRANNT, 

EDITOR  OF  "  THE  TECHNO-CHEMICAL  RECEIPT  BOOK." 


ILLUSTRATED  BY  TWENTY-FIVE  ENGRAVINGS. 


PHILADELPHIA: 
HENRY   CAREY    BAIRD    &    CO., 

INDUSTRIAL  PUBLISHERS,  BOOKSELLERS  AND  IMPORTERS. 

810  WALNUT  STREET. 

1892. 


COPYRIGHT  BY 

HENRY  CAEEY  BAIRD  &  CO. 

1891. 


PRINTED  AT  THE  COLLINS  PRINTING  HOUSE, 

705  Jayne  Street, 
•  PHILADELPHIA,  U.  S.  A. 


PREFACE. 


THIS  translation  of  Dr.  Felix  Wahnschaffe's 
Anleituny  zur  wissenschaftlichen  Bodenunter- 


>      suchung,  has  been  prepared  in  the  belief  that 
it  will  prove  of  interest  to  those  engaged  in 
cientific  agriculture  and  the  investigation  of 
agricultural  problems. 

Some  of  the  methods  of  analysis  described 
are  in  use  in  the  laboratory  of  the  Royal 
Prussian  Geological  Institute,  whilst  others 
have  been  taken  from  approved  text-books, 
but  in  many  respects  modified  by  Dr.  Wahn- 
schaffe.  Only  methods  yielding  scientifically 
useful  results,  and  of  comparatively  easy  and 
rapid  execution,  have  been  selected. 


405725 


IV  PREFACE. 

The  chapter  on  "The  Definition  of  the 
Soil,"  being  of  interest  only  to  German  readers, 
has  been  omitted,  and  a  few  trifling  changes 
and  additions  have  been  made. 

WILLIAM  T.  BRANNT. 

PHILADELPHIA,  December,  1891. 


CONTENTS. 


I.     DERIVATION  AND  FORMATION  OP  THE  SOIL. 

PAGE 

Various  modes  of  the  superficial  formation  of  the  earth's 
crust;  Forces  active  in  soil-formation;  Weathering  17 

Transformation  of  decomposable  minerals  contained  in 
rocks  .  . 18 

Process  of  kaolinization  ;  Denudation  of  the  soil         .     19 

II.     CLASSIFICATION  OF  SOILS. 

Lorenz  von  Liburnau's  system  ;  Primitive  soils  and  de- 
rived soils ;  Albrecht  Timer's  system  ;  Difficulty  of 
drawing  sharp  limits  in  the  classification  of  soils  .  21 

Importance  of  the  quantitative  determination  of  the 
principal  soil-constituents ;  Clay  the  most  important 
soil-constituent .22 

Loams  ;  Definition  of  the  terms  light  and  heavy  soils  ; 
Sub-soils ;  True  soils  or  top-soils  .  .  .  .23 

III.     THE  OBJECT  OF  SOIL-ANALYSIS. 

Soil-analysis  from  the  geological  and  agricultural  stand- 
points ;  Absorption  of  carbon  by  the  plant  .  .24 

Content  of  water  in  different  parts  of  plants  ;  Chemical 
combinations  found  in  plants  .  .  .  •  .25 

Elements  necessary  for  the  nourishment  of  plants  ;  Ele- 
ments occasionally  found  in  the  plant-ash          .         .26 
1* 


VI  CONTENTS. 


PAGE 


Execution  of  a  soil-analysis  which  is  to  satisfy  all  de- 
mands of  agriculture  ;  Importance  of  complete  exami- 
nations  27 

IV.     PREPARATORY  LABORS  FOR  SOIL-ANALYSIS. 

Taking  samples  from  the  soil  and  storing  and  preparing 
them  for  analysis 28 

Taking  specimens  of  salty  or  "alkali"  soils  ;  Depth  to 
which  samples  should  be  taken  .  .  .  .29 

Points  which  should  be  noted  in  taking  samples   .         .     30 

Labeling,  drying,  and  storing  samples  .         .         .31 

V.     MECHANICAL  SOIL-ANALYSIS. 

Granulating  with  the  sieve  .....     31 

Characterization  of  the  mechanical  composition  of  a 
soil ;  Preparations  for  the  execution  of  the  mechani- 
cal analysis     ...        ^.         ....     32 

Definitions  of  fine  soil  and  fine  earth  ;  Different  opinions 

as  to  what  constitutes  fine  soil  and  fine  earth    .         .     33 
Silt-analysis ;  Apparatuses  used  for  silt-analysis  ;  Noe- 
bel's  elutriating  apparatus        .         .         .         .         .34 

Products  of  elutriation  obtained  with  Noebel's  appara- 
tus ;  Schoene's  elutriating  apparatus ;  Definition  of 
velocity  of  elutriation      ......     36 

Schoene's  elutriator    .......     37 

Arrangement  for  the  elutriating  process        .         .         .38 
Formula  for  obtaining  the  elutriating  velocity      .         .     41 
Formulae  for  calculating  a  determined  elutriating  ve- 
locity       42 

Products  of  granulation  corresponding  to  elutriating  ve- 
locities .  .  ....  44 


CONTEXTS.  VI  i 

PAGE 
Orth's  auxiliary  cylinder ;  Scheme  of  a  table  to  be  used 

for  all  analyses  with  Schoene's  apparatus           .         .     45 
Execution  of  the  analysis  with  Schoene's  apparatus      .     46 
Apparatus  for  elutriation  with  distilled  water        .         .     47 
Products  obtained  by  the  elutriating  process         .         .     50 
Scheme  for  entering  the  figures  obtained  by  calculating 
the  products  of  granulation  and  elutriation  for  the  en- 
tire soil 51 

Hilgard's  elutriating  apparatus    .         .         .         .         .52 

Precautions  to  be  observed  in  order  to  insure  correct 
and  concordant  results     ......     54 

Lowest  velocity  available    .         .         .         .         .         .55 

VJ.     DETERMINATION  OF  THE  SOIL-CONSTITUENTS. 

Determination  of  the  content  of  calcium  carbonate  or 
of  magnesia  carbonate ;  Volumetric  measurement  of 
the  carbonic  acid .56 

Scheibler's  apparatus  for  the  volumetric  measurement 
of  the  carbonic  acid  .  .  .  .  .  .  57 

Table  for  calculating  the  carbonic  acid  for  Scheibler's 
apparatus  ........  60 

Table  for  calculating  the  carbonic  acid,  found  with 
Scheibler's  apparatus,  to  calcium  carbonate  .  .  61 

Determination  of  the  carbonic  acid  by  weighing  from 
the  loss ;  Mohr's  apparatus  modified  by  Laufer  and 
Wahnschafie  ........  62 

Determination  of  the  carbonic  acid  by  direct  weighing  ; 
R.  Finkener's  apparatus  .  .  .  .  .64 

Geissler's  potash  apparatus  .         .         .         .         .65 

Determination  of  the  carbonate  of  calcium  and  magne- 
sium by  boiling  with  ammonium  nitrate  .  .  .67 

Blast-lamp          .         .         .         .         .         .         .         .71 


Vlll  CONTENTS. 

PAGE 

Determination  of  the  humus  substances ;  Definition  of 
humus  ;  Neutral  and  acid  humus ;  Definition  of  peat  72 

Knop's  method  for  the  determination  of  humus  ;  Dr.  R. 
Muencke's  drying  chamber  .  .  .  .  .73 

Determination  of  the  carbon  of  the  humus  substances 
by  elementary  analysis  ...... 

Combustion  furnace 

Determination  of  the  loss  by  ignition  .         . 

Determination  of  the  content  of  clay   .... 

Disintegration  with  sulphuric  acid  in  a  closed  tube 

Tubular  furnace  ....... 

Separation  of  the  ferric  oxide  from  the  alumina  ;  Deter- 
mination of  the  iron  as  ferrous  oxide  by  titration  with 
potassium  permanganate  solution  .  .  .  .87 

Standardizing  of  the  potassium  permanganate  solution ; 
Purification  of  iron-ammonium  alum  or  ammonio- 
ferric  sulphate 90 

Formula  for  calculating  the  effective  value  of  the  potas- 
sium permanganate  solution  ;  Calculation  of  the  con- 
tent of  clay  in  the  total  soil  .  .  .  .  .92 

Determination  of  the  content  of  sand  ;  Petrographic  de- 
termination of  the  coarser  admixed  parts  of  the  sand  94 

Thoulet  and  Goldschmidt's  specifically  very  heavy 
fluids 95 

Rohrbach's  specifically  very  heavy  fluid  ;  Table  of  spe- 
cific gravities  of  various  minerals  ;  Determination  of 
the  content  of  quartz  ;  J.  Hazard's  method  .  .96 

Determination  of  the  elementary  composition  of  the  soil; 
Disintegration  with  sodium  carbonate  .  .  .99 

Disintegration  with  fluoric  acid 100 


CONTENTS.  IX 

VII.     DETERMINATION  OF  THE  PLANT-NOURISHING 

SUBSTANCES. 

PAGE 

Determination  of  the  plant-nourishing  substances  in  soil 
extractions  ;  Extraction  of  the  soil  with  cold  distilled 
water ;  Preparation  of  the  aqueous  extract  of  the  soil  102 

Determination  of  the  bases  in  the  aqueous  extract        .  103 

Covered  water-bath ;  Preparation  of  a  number  of  weighed 
filters 106 

Determination  of  the  acids  in  the  aqueous  extract ;  De- 
termination of  chlorine  ......  108 

Determination  of  sulphuric  acid  .....  109 

Determination  of  nitric  acid         .         .         .          .         .110 

Tiemann's  modification  of  Schloesing-Schulze's  method 
for  the  determination  of 'nitric  acid  .  .  .111 

Table  for  finding  the  tension  of  the  aqueous  vapor ; 
W.  "Wolf's  method  of  determining  the  nitric  acid  by 
means  of  zinc  in  alkaline  solution  .  .  .  .116 

Determination  of  the  ammonium  chloride  as  ammonio- 
platinum  after  the  conversion  of  the  nitric  acid  into 
ammonium  chloride 117 

Volumetric  determination  by  the  Knop- Wagner  azome- 
ter  of  the  nitrogen  in  the  ammonium  chloride  after 
converting  the  nitric  acid  into  ammonium  chloride  .  118 

The  Knop- Wagner  azometer        .         .         .         .         .119 

Dietrich's  table  for  the  absorption  of  nitrogen  in  60 
cubic  centimeters  developing  fluid  (50  cubic  centi- 
meters of  bromine  lye  and  10  cubic  centimeters  of 
water)  with  a  specific  gravity  of  the  lye  of  1.1  and 
such  a  strength  that  50  cubic  centimeters  correspond 
to  200  cubic  centimeters  of  nitrogen,  with  an  evolu- 
tion of  1  to  100  cubic  centimeters  of  nitrogen  .  .  122 

Special  method  in  the  examination  of  peat ;  Extraction 
of  soil  with  carbonated  water  .  .  .  123 


X  CONTENTS. 

PAGE 

Precipitation  of  the  phosphoric  acid  with  ammonium 
molybdate  and  weighing  as  magnesium  pyrophosphate  126 

Determination  of  the  phosphoric  acid  as  ammonium  phos- 
pho-molybdate,  according  to  R.  Finkener  .  .127 

Finkener's  drying  stand      .         .         .         .         .         .128 

Further  treatment  of  the  soil  extract  prepared  with  car- 
bonated water  .  .  .  .  .  .  .129 

Extraction  of  the  soil  with  cold  concentrated  hydrochlo- 
ric acid  ;  Extraction  of  the  soil  with  boiling  concen- 
trated hydrochloric  acid  .  .  .  .  .  .130 

Erlenmeyer  boiling  flask  and  sand-bath        .         .         .131 

Determination  of  some  important  substances  for  the  nour- 
ishment of  plants,  which  can  either  not  or  only  parti- 
ally be  determined  in  the  soil  extracts  ;  Determination 
of  the  total  nitrogen  in  the  soil;  Kjeldahl's  method  .  133 

Determination  of  the  nitrogen  by  combustion  with  soda 
lime 135 

Determination  of  the  ammonia  contained  in  the  soil     .  137 

Schoesing's  modified  method  for  the  accurate  determina- 
tion of  the  ammonia  in  the  soil  ».^  •  .  .  .138 

VIII.  DETERMINATION  .OP  THE  SUBSTANCES  IN 
THE  SOIL  INJURIOUS  TO  THE  GROWTH 
OF  PLANTS. 

Proof  of  the  presence  of  free  humic  acids  in  the  soil    .  139 
Determination  of  common  salt  in  the  soil ;  Determina- 
tion of  ferrous  sulphate,  free  sulphuric  acid,  and  iron 
disulphide ;  Methods  used  at  the  Prussian  moor  ex- 
perimental station  at  Bremen  .         .         .         .         .140 
Determination  of  the  content  of  sulphur  in  the  soil  by 
ignition  .         .         .          .         .         .         .141 


CONTENTS.  XI 

PAGE 

Fleischer's  method  of  calculating  the  sulphuric  acid 
present  in  a  form  injurious  to  plants  ;  Determination 
of  the  content  of  sulphur  in  the  soil  by  disintegration 
with  bromine  .  .  .  .  .  .  .143 

IX.     DETERMINATION  OF  VARIOUS  PROPERTIES  OP 

THE  SOIL  WHICH  ARE  DEPENDENT  PARTI- 
ALLY ON  PHYSICAL  AND  PARTIALLY  ON 
CHEMICAL  CAUSES. 

Weight  of  the  soil ;  Determination  of  the  specific  gravity  144 

Determination  of  the  volume  weight ;  Apparent  specific 
gravity  of  the  soil;  Porosity  of  the  soil  .  .  .145 

Behavior  of  the  soil  towards  nourishing  substances       .  146 

Testing  the  absorbent  power  of  the  soil  with  -^  or  TJ^ 
normal  solutions ;  Salts  suitable  for  these  experi- 
ments ;  Preparation  of  the  j1^  normal  solution ; 
Fesca's  method  of  preparing  monocalcium  phosphate  147 

Determination  of  the  absorption  .         .         .         .148 

Determination  of  the  absorption-coefficient  according  to 
Knop 149 

Behavior  of  the  soil  towards  water  ;  Power  of  retaining 
moisture  in  the  soil ;  By  experiments  in  the  labora- 
tory   151 

Definition  of  the  greatest  or  full  capacity  for  water ;  Zinc 
tubes  used  in  determining  the  power  of  the  soil  to  re- 
tain water  .  .  .  .  .  .  '  *  .  152 

A.  Mayer's  method  for  determining  the  power  of  the 
soil  to  retain  water ;  Determination  of  the  water  ca- 
pacity of  the  soil  in  its  natural  bed  in  the  open  field  154 

Heinrich's  modified  method ;  The  evaporating  power 
of  the  soil ;  E.  Wolff's  method  of  determining  the 
evaporating  power  of  the  soil 156 


Xll  CONTENTS. 

PAGE 

The  filtrating  power  of  the  soil ;  E.  Wolff's  method     .  157 

Capillary  attraction  of  the  soil ;  Apparatus  used  for  the 
purpose 158 

Behavior  of  the  soil  towards  gases ;  The  absorbent  ca- 
pacity of  the  soil  for  aqueous  vapor  .  .  .  159 

The  absorbent  power  of  the  soil  for  the  oxygen  of  the 
atmospheric  air  ;  "W.  Wolf's  method  .  .  .  1 60 

F.  Schulze's  method  of  determining  the  absorption-coef- 
ficient of  the  soil  for  oxygen  ;  G.  Ammon's  summary 
of  his  experiments 161 

The  ventilating  power  of  the  soil ;  R.  Heinrich's  method 
and  apparatus  used  .  .  .  .  .  .162 

Behavior  of  the  soil  towards  heat ;  Determination  of  the 
heat-absorbent  power  of  the  soil  .  .  .  .  ]  63 

On  what  the  heating  capacity  of  a  soil  is  dependent      .  164 

The  heat-conducting  power  of  the  soil;  Wollny's  de- 
ductions from  his  experiments  ....  165 

Cohesion  and  adhesion  of  the  soil;  R.  Heinrich's  method 
of  determining  the  coherence  of  the  soil  in  a  wet  state  166 

R.  Heinrich's  directions  for  determining  the  adhesion  of 
moist  soils  to  iron  and  wood 167 

X.     GENERAL  RULES  FOE  SOIL- ANALYSIS. 

Necessity  of  fixed  rules  in  order  to  obtain  comparable 
results  .  .  .  .  .  .  .  .  .167 

Summary  of  general  rules  to  be  applied  to  the  examina- 
tion of  soils  168 

INDEX     .  171 


THE  EXAMINATION  OF  SOILS. 


i. 

DERIVATION  AND  FORMATION  OF  THE  SOIL. 

THE  superficial  formation  of  the  earth's  crust,  which 
serves  as  the  bearer  and  nourisher  of  plants,  is  effected 
either  by  the  loosening  and  decomposition  of  the  exposed 
rocks,  or  by  the  transport  of  coarse  and  fine  materials 
worn  from  other  rocks,  or,  finally,  by  the  transforma- 
tion into  humus  of  decayed  vegetable  remains  piled  up 
in  large  masses. 

The  forces  active  in  the  first-mentioned  mode  of  soil- 
formation  are  partially  of  a  physical  and  partially  of  a 
chemical  nature.  Their  co-operation  is  called  weather- 
ing, and  will  have  to  be  considered  somewhat  more 
closely.  First  of  all,  it  is  heat  which,  by  itself  as 
well  as  in  conjunction  with  water,  prepares  the  rock 
for  the  further  disintegrating  process.  In  consequence 
of  changes  in  temperature  small  cracks  and  fissures  are 
gradually  formed  in  the  rock  by  the  uu equal  expansion 
and  contraction  of  the  different  minerals  occurring  in  it. 
When  it  rains  the  water  flows  down  through  all  these 
cracks  and  lodges  in  countless  minute  fissures'  in  the  face 
of  the  rock.  After  a  heavy  rain,  when  the  rock  is  filled 
with  water,  it  may  clear  away  and  a  sharp  frost  set  in. 
2 


18  THE   EXAMINATION   OF   SOILS. 

Every  drop  of  water  freezes  and  expands  and  bursts 
open  the  rock,  splitting  off  minute  specks  and  scales  or 
throwing  down  great  lumps.  In  the  summer  there  is 
no  frost,  and  yet  the  rain  may  be  at  work  washing  moss 
and  dust  into  the  cracks  already  opened  and  forming  a 
sponge  ready  to  hold  water  that,  freezing  next  winter, 
will  act  with  still  greater  force.  The  dry  dust  sifted 
into  the  cracks  and  openings  in  the  rock  will  also  ex- 
pand w<hen  wet  and  push  off  small  pieces,  or  start  a 
great  mass  that  last  winter's  ice  left  just  ready  to  fall. 
These  disintegrating  agencies  are  still  further  aided  by 
the  root-growth  of  plants,  by  the  burrowing  of  worms 
and  other  earth-delving  creatures,  and  in  no  small  de- 
gree by  the  generation  of  organic  acids — humic,  crenic, 
etc. — by  organic  decay. 

Furthermore,  rocks  containing  decomposable  minerals 
undergo  a  chemical  process  of  transformation  in  which 
the  oxygen  of  the  atmospheric  air  and  water,  as  well  as 
the  carbonic  acid  dissolved  in  the  latter,  are  the  chief 
agents.  The  oxygen  converts  the  metallic  protoxides 
in  the  rocks  into  oxides,  and,  since  water  is  almost  always 
present,  into  hydroxides.  Ferrous  oxide  combined  with 
silica  is  in  this  manner  changed  to  ferric  hydrate.  By 
this  process  the  texture  of  minerals  containing  ferrous 
silicate — as,  for  instance,  many  feldspars,  certain  micas, 
hornblende,  and  augite  (pyroxene) — is  loosened.  Rocks 
distinguished  by  the  occurrence  in  them  of  metallic  sul- 
phides, to  which  among  the  sedimentary  rocks  chiefly 
belong  the  clay-slates,  bituminous  marls,  and  clays,  are 
decomposed  by  the  conversion  of  their  metallic  sulphides, 
on  coming  in  contact  with  moist  air,  into  sulphates  or 
vitriols.  By  the  lixiviation  of  the  latter  by  water,  the 


DERIVATION    AND    FORMATION    OF   THE   SOIL.       19 

rock  becomes  porous  and  cellular,  and  finally  breaks  up 
into  fragments. 

The  process  of  kaolinization  is  due  to  the  action  of 
waters  containing  carbonic  acid  upon  silicious  rocks 
rich  in  alkalies  (potash  and  soda)  and  alkaline  earths 
(calcareous  earth,  magnesia).  By  such  waters,  which 
acquire  their  carbonic  acid,  partially  from  the  atmo- 
sphere, and  partially  from  the  organisms  decaying  upon 
the  surface,  the  alkalies  and  alkaline  earths  are  converted 
into  carbonates  and  bicarbonates,  while  silica  is  sepa- 
rated. The  carbonates  and  bicarbonates  are  soluble  in 
water,  and,  together  with  the  separated  gelatinous  silica, 
are  carried  away  by  the  water,  while  a  silicate  of  alu- 
minium containing  water — the  kaolin — remains  behind. 
For  this  theory  of  the  formation  of  kaolin  we  are  in- 
debted to  Forchhammer.  It  takes  place,  for. instance, 
in  orthoclase,  which  consists  of  one  molecule  potash,  one 
molecule  alumina,  and  six  molecules  silica,  by  the 
separation  of  four  atoms  silica  and  one  atom  potash, 
while  the  remaining  alumina  combines  with  two  mole- 
cules silica  and  two  molecules  water  to  kaolin  and  clay. 

Denudation  of  the  soil. — The  rain  falling  on  the  wast- 
ing rocks  sweeps  away  the  minute  specks  and  grains 
chipped  off  by  the  weather  and  carries  them  down  to 
the  nearest  streamlet  and  brook.  These  fine  bits  of  rock 
do  not  float,  but  are  suspended  in  the  water  or  roll  along 
the  bed  of  the  stream.  The  ragged  flakes  and  scales  of 
stone  crash  and  grind  against  each  other.  Every  rough 
corner  is  knocked  off,  and  all  the  pieces  become  rolled 
into  smooth  round  particles.  The  brook  is  a  mill.  It 
is  making,  from  the  chips  brought  down  by  the  rain, 
sand.  A  flood  comes  with  more  water,  and  larger  pieces 


o 


20  THE    EXAMINATION   OF   SOILS. 

of  rock  are  pushed  into  the  rapidly  moving  water,  and 
these  knocking,  tumbling,  and  grinding  over  each  other, 
are  soon  ground  into  smooth  round  pebbles  and  gravel. 
Onward  rolls  the  confused  mass  of  gravel,  sand,  and 
finer  bits  of  rocks,  grinding  and  polishing  each  piece 
as  it  goes.  In  time  the  stream  comes  to  more  level 
ground  and  runs  slower  and  slower.  The  current, 
not  being  able  to  push  the  larger  stones  any  further, 
leaves  them  all  by  themselves.  Thus  the  trans- 
ported matter  is  gradually  deposited  as  the  current 
diminishes  in  velocity,  the  very  finest  particles  being 
carried  as  long  as  the  stream  remains  in  motion.  When 
the  river  reaches  a  flat  or  level  tract,  and  over  which  its 
waters  can  flow  in  flood  with  a  slow  motion,  the  sus- 
pended' matter,  consisting  principally  of  sand  and  mud, 
is  deposited  and  constitutes  the  alluvium  or  new  land, 
formed  by  such  deposits  at  the  river's  mouth  and  along 
its  banks.  Though  the  soil  is  thus  continuously  washed 
away,  still  it  remains  nearly  constant  in  quantity,  since 
what  is  taken  away  by  denudation  is  made  up  from 
other  causes,  and  this  augmentation  can  evidently  pro- 
ceed from  nothing  but  the  slow  and  constant  disintegra- 
tion of  the  rocks. 

The  rocks  which  weather  most  easily  and  rapidly  do 
not  always  exhibit  most  soil ;  very  often  the  reverse.  A 
pure  limestone  would  show  hardly  any  weathered  band 
or  soil,  because  the  carbonic  acid  of  the  rain  would 
almost  at  once  dissolve  and  remove  the  particles  it  acts 
upon.  Even  in  the  case  qf  igneous  rocks,  their  com- 
position may  be  such  that  those  which  weather  the  most 
rapidly  would,  likewise,  show  little  of  a  weathered 
baud,  owing  to  the  same  solvent  action. 


CLASSIFICATION    OF   SOILS.  21 

II. 

CLASSIFICATION  OF    SOILS. 

IN  conformity  with  Lorenz  von  Liburnau's  system, 
soils  may  preferably  be  divided,  according  to  their  forma- 
tion, into  two  large  principal  groups,  viz.,  primitive  soils 
and  derived  soils.  Primitive  or  original  soils  may  be 
called  such  as  have  been  directly  formed  by  the  weather- 
ing of  exposed  rocks,  or,  like  peat,  by  the  decomposition 
of  vegetable  remains  in  their  original  place  of  location. 
According  to  the  original  structure,  a  distinction  has  to 
be  made  between  primitive  soils  of  the  crystalline  and 
of  the  sedimentary  rocks,  as  well  as  of  the  peat  forma- 
tions. Derived  soils  (deposited  or  transported  soils)  are 
such  as  have  been  transported  either  in  a  solid  or  liquid 
form  by  water,  or,  also,  by  the  wind. 

For  the  further  classification  of  soils  it  is  preferable 
to  make  use  of  the  physical  system  of  soil  classification 
proposed  by  Albrecht  Thaer,  the  founder  of  scientific 
agriculture.  He  distinguishes  the  varieties  of  soil  ac- 
cording to  the  predominance  in  them  of  the  admixed 
parts  of  what  may  be  called  the  principal  soil  con- 
stituents. From  this  result  the  following  groups  of 
soils:  1.  Stony  soils.  2.  Sand  soils.  3.  Loam  soils. 
4.  Clay  soils.  5.  Marl  soils.  6.  Lime  soils.  7. 
Humus  soils. 

The  same  experience  met  everywhere  in  nature  that 
sharp  limits  cannot  be  drawn  in  the  classification  of 
animate,  as  well  as  inanimate  bodies,  shows  itself  in  the 


22  THE   EXAMINATION   OF   SOILS. 

division  of  soils,  the  above-mentioned  groups  exhibiting 
very  gradual  transitions  into  each  other,  and  even,  like 
the  clay  and  inarl  soils,  are  already  partially  transition 
formations. 

A  single  principal  constituent,  be  it  sand,  clay,  lime, 
or  humus,  cannot  afford  to  cultivated  plants  an  adequately 
fertile  soil ;  the  more  uniformly  all  the  constituents 
participate  in  the  composition  of  the  soil,  the  greater  its 
value  and  yield  will  be.  Hence,  the  quantitative  de- 
termination of  the  principal  constituents  is  an  important 
task  of  scientific  soil-analysis,  since,  on  their  proportions 
to  each  other,  the  value  of  the  soil  for  cultivation  de- 
pends. As  is  well  known  by  a  greater  or  smaller  con- 
tent  of  clay,  a  sand-soil  gains  essentially  in  the  power 
of  holding  water  and  in  absorbent  capacity.  But  the 
physical  properties  of  a  clay-soil  are  also  improved  by  a 
content  of  sand,  it  becoming  thereby  more  friable,  more 
permeable,  and  more  easy  to  cultivate.  Of  still  greater 
importance  to  agriculture  is  a  lime  soil  combined  with 
sand  and  clay — hence,  the  more  it  apporaches  a  marl 
soil — while  an  extreme  humus  soil  (peat)  first  requires 
special  meliorations  to  make  it  fit  for  cultivation. 

It  is  not  to  be  understood  that  in  naming  the  varieties 
of  soils  after  the  principal  constituent,  the  admixed  part 
reaching  the  highest  number  of  per  cent,  furnishes  the 
name,  this  being  the  case  only  with  sand  and  lime  soils. 
On  the  contrary,  it  is  rather  the  physically  most  import- 
ant admixed  part,  which  has  to  be  considered  as  the  guide 
in  this  respect,  even  if  it  is  not  represented  by  a  relatively 
high  number  of  per  cent,  in  the  composition  of  the  soil. 
Thus  clay  is  the  most  important  soil  constituent  so  long  as 
its  physical  properties  are  not  covered  or  invalidated  by 


CLASSIFICATION   OF   SOILS.  23 


another  u<lniLir<l  jx/rf.  If,  for  instance,  this  is  done  by 
sand,  a  soil  when  no  longer  plastic,  but  only  binding, 
has  to  be  classed  among  the  loam  soils.  With  a  still 
greater  content  of  sand,  the  soil  also  loses  its  binding 
power,  and  we  have  then  a  sandy  loam  or  a  loamy  sand. 

Loams  which  may  be  considered  as  typical  soils  are  a 
mixture  of  sand,  clay,  and  humus,  which  are  spoken  of 
as  light  when  the  sand  predominates,  and  as  heavy  when 
the  clay  is  in  excess.  These  terms,  light  and  heavy,  do 
not  refer  to  the  actual  weight  of  the  soil,  but  to  its 
tenacity  and  the  degree  of  resistance  it  offers  to  the  im- 
plements used  in  cultivation.  Sandy  soils  are,  in  the 
farmer's  sense  of  the  word,  the  lightest  of  all  soils,  because  / 
they  are  the  easiest  to  work,  whilst  in  actual  weight  they  \ 
are  the  heaviest  soils  known.  Clay,  though  hard  to 
work  on  account  of  its  tenacity,  is  comparatively  a  light 
soil  in  weight.  Peaty  soils  are  light  in  both  senses  of 
the  word,  they  being  loose  or  porous  and  having  little 
actual  weight. 

Besides  the  soils  proper  which  come  immediately  under 
cultivation,  there  are  in  most  places  a  set  of  subsoils  which 
differ  from  the  true  soils,  and  which  cannot  be  ignored. 
The  true  soils,  or,  as  they  are  sometimes  called,  the  top 
soils,  are  usually  of  a  darker  color  from  the  larger  ad- 
mixture of  humus,  whilst  the  subsoils  are  lighter  in  hue, 
yellow,  red  or  bluish  from  the  greater  preponderance  of 
the  iron  oxides.  The  soils  are  more  or  less  friable  in 
their  texture,  whilst  the  subsoils  are  tougher,  more  com- 
pact, and  more  largely  commingled  with  rubbish  and 
stone.  The  soils  are  usually  a  little  more  than  mere  sur- 
face coverings,  whilst  the  subsoils  may  be  many  feet  in 
thickness. 


24  THE   EXAMINATION   OF  SOILS. 


III. 

THE  OBJECT  OF   SOIL-ANALYSIS. 

IN  the  analysis  of  soils  we  may  be  guided  by  geological 
or  agricultural  considerations. 

From  a  purely  geological  standpoint,  the  determina- 
tion of  the  petrographic  composition  of  the  soil,  as  well 
as  that  of  its  relations  to  the  mother  rock — the  weather- 
ing process — will  chiefly  be  of  interest.  But,  since  the 
soil  is  of  importance  principally  in  an  agricultural 
respect,  it  is  also  the  object  of  most  of  the  analyses  of  it 
to  solve  scientific  and  practical  questions  relating  to 
agriculture  as  well  as  to  a  knowledge  of  the  soil,  and 
though  the  latter  is  an  agronomic  science,  it  must  rest 
upon  a  geologico-petrographic  basis. 

Those  times  in  which  the  soil  was  simply  considered 
the  bearer,  but  not  the  nourisher  of  plants,  and  when  it 
was  believed  that  only  its  physical  properties  exerted  an 
influence  upon  vegetation,  have  long  since  passed.  To- 
day it  is  well  known  that,  though  the  production  of 
plants  is  materially  influenced  by  these  physical  pro- 
perties, it  does  not  exclusively  depend  upon  it. 

One  of  its  principal  constituents — carbon — the  plant 
absorbs  directly  from  the  atmospheric  air,  whilst  all  the 
remaining  substances  required  for  its  nourishment  and 
development,  it  obtains,  partially  directly  and  partially 
indirectly,  from  the  soil.  Since  soil-analysis  has  for  its 
object  the  determination  of  the  nourishing  matters  of  the 


THE   OBJECT   OF   SOIL-AXA  LYSIS.  25 

plant,  the  elementary  substances  of  the  latter  shall  be 
briefly  discussed. 

All  the  living  parts  of  plants  contain  a  large  quantity 
of  water,  which  not  only  forms  a  principal  constituent 
of  the  juice,  but  also  saturates  all  membranes  and  the 
protoplasm.  In  the  substance  of  all  organized  vegetable 
structures  small  particles  of  water  are  stored.  This 
water,  which  is  absolutely  necessary  for  vegetation, 
escapes  on  heating  the  parts  of  plants  for  some  time  to 
from  212°  to  230°  F.  The  content  of  water,  which  is 
to  be  calculated  from  the  decrease  in  weight,  varies  very 
much  in  the  different  parts  of  plants,  it  amounting,  for 
instance,  in  dry  seeds  to  from  12  to  15  per  cent.,  in  juicy 
plants  to  from  60  to  80  per  cent.,  and  in  aquatic  plants 
and  fungi  up  to  95  per  cent.  The  plant  obtains  the 
water  directly  from  the  soil,  since  on  account  of  its 
capillary  structure  it  possesses,  similar  to  a  sponge,  the 
capacity  of  absorbing  and  retaining,  to  a  more  or  less 
degree,  the  water  offered  to  it. 

In  the  parts  of  plants  dried  at  230°  F.  a  large  num- 
ber of  chemical  combinations  are  found,  of  which  those 
representing  chemical  unions  of  carbon  with  other  ele- 
ments are  designated  as  organic  combinations.  By 
incineration  the  organic  combinations  are  destroyed,  while 
the  inorganic  combinations  of  the  plant  substance  remain 
behind  as  a  white  ash.  It  may  here  be  mentioned  that  in 
the  incineration  of  the  plants,  the  sulphur,  which  forms  a 
constituent  of  the  organic  combinations,  also  reaches,  by 
chemical  processes,  the  ash  in  which  it  is  found  as  sul- 
phate. Furthermore,  the  carbonic  acid  formed  during 
incineration  and  which  combines  with  the  inorganic 
substances  of  the  residue,  must  also  be  left  out  of  con- 


26  THE   EXAMINATION   OF   SOILS. 

sideration  in  analyzing  the  ash.  The  organic  combina- 
tions occurring  in  larger  quantities  in  plants  consist  of 
carbon  and  hydrogen,  or  of  carbon,  hydrogen,  and  oxy- 
gen, or  of  carbon,  hydrogen,  nitrogen,  and  sulphur. 

By  experiments  it  has  been  determined  that  certain 
inorganic  substances  are  not  accidentally  admixed  parts 
of  the  plant,  but  are  absolutely  necessary  for  its  life  and 
growth,  and  consequently  for  the  formation  of  the  above- 
mentioned  organic  combinations. 

The  elements  which  are  necessary  for  the  nourishment 
of  the  plants  may,  according  to  their  uses,  be  divided  as 
follows : — 

Elements  for  ike  formation  of  the  organic  combina- 
tions.— Carbon,  hydrogen,  oxygen,  nitrogen,  sulphur, 
and 

Elements  for  the  formation  of  the  inorganic  combina- 
tions.— Phosphorus,  chlorine,  potassium,  calcium,  mag- 
nesium, and  iron. 

Besides  these,  some  other  elements  are  occasionally 
found  in  the  plant-ash,  as,  for  instance,  sodium,  lithium, 
manganese,  silicium,  iodine,  bromine,  and,  very  seldom, 
aluminium,  copper,  zinc,  nickel,  barium;  but  are  of  no 
importance  in  the  nourishment  of  the  plants. 

From  the  above  it  follows,  that  in  examining  the  soil 
as  to  its  content  of  plant-nourishing  substances,  the 
eight  following  elements,  independent  of  oxygen  and 
hydrogen,  have  to  be  taken  into  consideration,  namely : 
nitrogen,  sulphur,  phosphorus,  chlorine,  potassium,  cal- 
cium, magnesium,  and  iron. 

Since,  as  previously  indicated,  the  thriving  of  the  plant 
depends  not  only  on  the  chemical  composition  of  the 
soil,  but  also,  in  a  high  degree,  on  its  mechanical  mixture 


THE    OBJECT   OF   SOIL-ANALYSIS.  27 

and  physical  properties,  a  soil  analysis  which  is  to  satisfy- 
all  demands  of  agriculture  has  to  be  executed  as  fol- 
lows : — 

1.  The  mechanical  mivtitre  of  the  soil  must  be  quan- 
titatively determined.     This  examination  may  be  desig- 
nated mechanical  noil  analysis. 

2.  The  soil-constituents,  sand,  day,  humus,  lime,  have 
to  be  quantitatively  determined.     This  is  partially  af- 
fected   by   the   mechanical    analysis   and    partially    by 
chemical  methods  of  analysis  executed  on  the  one  hand, 
independent  of  the    mechanical    analysis,    and   on    the 
other,  in  connection  with  it. 

3.  The  content  of  plant-nourishing  substances  in  the  soil 
has  to  be  determined  by  chemical  analysis. 

4.  The  substances  injurious  to  the  vegetable  world  must 
be  taken  into  consideration. 

5.  Experiments  have  to  be  made  to  gain  direct  in- 
formation in  regard  to  certain  properties  of  the  soil,  which 
depend  partially  on  physical  and  partially  on  chemical 
causes. 

Such  complete  examinations  are  of  great  importance 
for  judging  the  soil,  but  it  must  be  borne  in  mind  that 
by  them  alone  its  value  cannot  be  determined.  The 
greater  or  inferior  fertility  of  a  soil  depends  not  only  on 
its  mechanical  and  chemical  composition,  but  also  on 
various  conditions  outside  of  them;  for  instance,  the 
more  or  less  inclined,  as  well  as  the  higher  or  lower 
location  of  the  soil,  the  condition  of  the  subsoil,  the 
underground  water,  exposure  to  the  sun,  climate,  etc. 


28  THE   EXAMINATION   OF   SOILS. 


IV. 

PREPARATORY  LABORS  FOR  SOIL-ANALYSIS. 

BEFORE  entering  upon  the  methods  of  analysis  it  will 
be  necessary  to  discuss  the  labors  which  must  precede  them. 
They  consist  in  taking  samples  from  the  soil  and  storing 
and  preparing  them  for  analysis. 

In  the  same  field  different  varieties  of  soil  often  occur, 
and  some  recommend  that  in  collecting  a  specimen  for 
analysis,  portions  should  be  taken  from  different  parts 
of  the  field  and  mixed  together,  by  which  an  average 
quality  of  soil  would  be  obtained.  But  this  is  bad 
advice  when  the  soils  in  different  parts  of  the  field  are 
really  unlike.  Suppose  one  part  of  a  field  to  be  clay  and 
another  sandy,  as  is  often  the  case  in  most  countries,  and 
that  an  average  mixture  of  the  two  varieties  of  soil  is 
submitted  to  the  analysis ;  the  result  obtained  will  apply 
neither  to  the  one  part  of  the  field  nor  to  the  other,  that 
is,  it  will  be  of  little  or  no  practical  value.  In  taking 
samples  it  is,  therefore,  recommended  not  to  select  mixed 
average  samples,  but  characteristic  separate  samples. 

After  selecting  a  proper  spot,  pull  up  the  plants  grow- 
ing on  it  and  scrape  off  the  surface  lightly  with  a  sharp 
tool,  to  remove  half-decayed  vegetable  matter  not,  as  yet, 
forming  part  of  the  soil.  Dig  a  vertical  hole,  like  a 
post-hole,  at  least  twenty  inches  deep.  Scrape  the  sides 
clean,  so  as  to  see  at  what  depth  the  change  of  tint 
occurs  which  marks  the  downward  limit  of  the  surface 
soil  and  record  it.  Take  at  least  half  a  bushel  of  the 


PBEPABATORY    LABOBS    FOE   SOIL- ANALYSIS.       29 

earth  above  this  limit,  and,  on  a  cloth  or  paper,  break  it 
up  and  mix  it  thoroughly,  and  put  up  at  least  a  quart  of 
it  in  a  sack  or  package  for  examination.  This  specimen 
will  ordinarily  constitute  the  "soil."  Should  the  change 
of  color  occur  at  a  less  depth  than  six  inches,  the  fact 
should  be  noted,  but  the  specimen  taken  to  that  depth 
nevertheless,  since  it  is  the  least  to  which  rational  culture 
cau  be  supposed  to  reach. 

In  case  the  difference  in  the  character  of  a  shallow  sur- 
face soil  and  its  subsoil  should  be  unusually  great,  as  may 
be  the  case  in  tule  or  other  alluvial  lands  or  in  rocky 
districts,  a  separate  sample  of  that  surface  soil  should  be 
taken  besides  the  one  to  the  depth  of  six  inches. 

Specimens  of  salty  or  "  alkali"  soils  should,  as  a  rule, 
be  taken  only  toward  the  end  of  the  dry  season,  when 
they  will  contain  the  maximum  amount  of  the  injurious 
ingredients  which  it  may  be  necessary  to  neutralize. 

Whatever  lies  beneath  the  line  of  change,  or  below  the 
minimum  depth  of  six  inches,  will  constitute  the  subsoil. 
But,  shoukl  the  change  of  color  occur  at  a  greater  depth 
than  twelve  inches,  the  "soil"  specimen  should,  never- 
theless, be  taken  to  the  depth  of  twelve  inches  only, 
which  is  the  limit  of  ordinary  tillage;  then  another 
specimen  from  that  depth  down  to  the  line  of  change, 
and  the  subsoil  specimens  beneath  that  line.  The  depth 
down  to  which  the  last  should  be  taken  will  depend  on 
circumstances.  It  is  always  desirable  to  know  what 
constitutes  the  foundation  of  a  soil  down  to  the  depth  of 
three  feet  at  least,  since  the  question  of  drainage;  resist- 
ance to  draught,  etc.,  will  depend  essentially  upon  the 
nature  of  the  substratum.  But  in  ordinary  cases  ten  or 
twelve  inches  of  subsoil  will  be  sufficient  for  the  purpose 


30  THE   EXAMINATION   OF   SOILS. 

of  examination  in  the  laboratory.  The  specimen  should 
be  taken  in  other  respects  precisely  like  that  of  the  surface 
soil,  while  that  of  the  material  underlying  this  "  subsoil" 
may  be  taken  with  less  correctness,  perhaps  at  some  ditch 
or  other  easily  accessible  point,  and  should  not  be  broken 
up  like  the  other  specimens.* 

At  the  same  time  when  taking  samples,  the  general 
condition  of  the  soil  should  be  noted  and  accurate  in- 
formation gained  chiefly  in  regard  to  the  following 
points : — 

1.  The  geological  origin  and  petrographic  nature  of 
the  soil. 

2.  The  relations  of  the  foundation  of  the  soil  to  a 
depth  of  six  feet  if  possible. 

3.  The  thickness  of  the  surface  soil. 

4.  The  location  of  the  soil  above  the  level  of  the  sea. 

5.  The  inclination  of  the  soil. 

6.  The  height  of  the  underground  water. 

7.  The  climatic  conditions  of  the  region. 

8.  The  judgment  of  a  practical  agriculturist  residing 
in  the  neighborhood  in  regard  to  the  quality  and  yield- 
ing capacity  of  the  soil. 

9.  The  manner  and  quantity  of  manuring  the  soil  has 
received  in  the  preceding  years. 

10.  The  meliorations  (marling,    draining,  irrigation, 
etc.)  which  may  have  been  made. 

1 1 .  The  lowest  yields  and  rotation  of  crops. 

In  fact,  every  circumstance  that  can  throw  light  on 
the  agricultural  qualities  or  peculiarities  of  soil  and 
subsoil  should  be  carefully  noted. 

*  Soil  Investigation,  by  E.  W.  Hilgard,  in  Tenth  Census  of  the 
U.  S.,  vol.  5.  Cotton  Production,  Washington,  1884. 


MECHANICAL   SOIL-ANALYSIS.  31 

It  is  recommended  to  immediately  label  each  sample. 

In  summer,  the  sample  is  allowed  to  dry  out  slowly 
in  the  air,  and  in  winter,  in  a  moderately  warm  room 
until  it  shows  a  quite  equal  and  constant  weight.  In 
this  condition  it  is  called  air-dry  soil.  If  the  sample  has 
to  be  kept  any  length  of  time,  it  is  recommended  to  store 
it  in  wide-mouthed  glass  bottles  hermetically  closed,  as 
otherwise  it  might  undergo  changes  in  the  laboratory 
where  vapors  of  ammonia  and  acids  cannot  always  be 
avoided.  Clayey  and  humus  varieties  of  soils  possess 
the  property  of  absorbing  ammoniacal  vapors,  and,  hence, 
if  the  sample  has  for  a  long  time  remained  unprotected 
in  the  laboratory,  the  analysis  would  show  too  high  a 
content  of  nitrogen. 


V. 

MECHANICAL  SOIL-ANALYSIS. 

THE  object  of  mechanical  soil-analysis  is  the  quan- 
titative determination  of  the  proportional  quantities  of 
coarser  and  finer  constituents  composing  the  soil.  To 
attain  such  a  mechanical  separation  of  the  soil  two 
mediums  are  employed — granulating  with  the  sieve,  and 
elutriating  with  water  or  silt  analysis. 

A.  Granulating  with  the  sieve, — For  the  examination 
of  soils  with  coarser  constituents,  granulation  with  the 
sieve  should  always  precede  silt-analysis,  since  such  soils 
cannot  be  well  brought  into  the  elutriating  apparatus, 
and,  even  if  this  were  possible,  would  clog  it.  Sieves 


32 


THE   EXAMINATION   OF   SOILS. 


with  round  holes  are  to  be  preferred  to  square-meshed 
sieves,  they  permitting  more  accurate  measurements. 

In  order  to  sufficiently  characterize  the  mechanical 
composition  of  a  soil,  and  to  compare  it  with  other 
varieties,  the  soil  is  divided  into  the  following  pro- 
ducts :  — 


£-  P  '** 

l^l-*-t>C 


Grains  larger  than    2  millimeters  in  diameter. 


' 

2. 

from     2  to      1 

3. 

1        Ito  0.5 

-t-i-^n  <JX*V 

4. 

'    0.5  to  0.2 

^H-U  ,SW  5. 

'    0.2  to  0.1 

6. 

'     0.1  to  0.05 

~*L^-'  ' 

7. 

1  0.05  to  0.01 

-  O  -t    f<--7 

8. 

smaller  than  0.01 

The  sizes  of  grains  Nos.  1  to  3,  i.  e.,  to  0.5  millimeters 
in  diameter,  are  obtained  by  sifting  through  sieves  with 
holes  2,  1,  and  0.5  millimeters  in  diameter;  all  other 
products  of  granulation  are  separated,  as  will  be  shown 
later  on  by  silt  analysis. 

For  the  execution  of  the  mechanical  analysis,  spread 
the  air-dry  soil  out  upon  a  sheet  of  paper  or  in  a  shallow 
dish,  and,  after  finely  dividing  it  by  rubbing  between 
the  hands,  or  by  means  of  a  wooden  pestle  in  a  mortar, 
weigh  out  a  good  average  sample  of  500  to  100  grammes. 
For  weighing  all  the  products  of  granulation  obtained 
by  sifting  and  elutriating,  as  well  as  for  the  physical  ex- 
periments, an  accurate  balance  must,  of  course,  be  used. 
The  quantity  weighed  out  for  granulation  is  then  passed, 
in  a  dry  state,  through  the  2-millimeter  sieve. 

Since  the  entire  sample  of  soil  has  been  weighed,  it  is 
only  necessary  to  weigh  the  residue  remaining  in  the  2- 
millimeter  sieve.  The  quantity  of  soil  which  has  passed 
through  the  sieve  is  then  learned  from  the  difference 


MECHANICAL   SOIL-ANALYSIS.  33 

resulting  by  deducting  the  product  of  granulation  of  over 
2  millimeters  from  the  total  weight.  With  loamy  soils 
the  product  of  granulation  of  over  2  millimeters  must 
always,  before  weighing,  be  rinsed  off  with  distilled 
water  to  free  it  from  adhering  sand  and  loam,  then  dried 
at  212°  F.  upon  the  sand-bath,  and  weighed  only  when 
entirely  cold. 

The  soil  which  has  passed  through  the  2-millimeter 
sieve  will  be  designated  as  fine  soil.  It  forms  the  initial 
material  to  be  employed  in  the  silt  analysis  as  well  as  in 
the  chemical  investigations  in  the  execution  of  which  pro- 
ducts of  elutriation  are  not  to  be  used. 

Emil  Wolff  and  Schoene  designate  as  fine  earth  tfie 
soil  which  has  passed  through  a  3-millimeter  sieve. 
Kuop's  conception  is  a  still  different  one.  He  calls 
fine  earth  the  soil  which  has  passed  through  a  ^-mil- 
limeter sieve,  and  fine  soil  the  residue  resulting  from 
igniting  the  fine  earth.  M.  Fesca  applies  the  term,  fine 
soil  to  soil  less  than  4  millimeters  in  diameter. 

From  what  has  been  said  it  will  be  seen  that  there  is 
a  great  difference  in  the  ideas  of  agricultural  chemists  as 
to  what  constitutes  fine  soil  and  fine  earth,  and  yet  it  is 
absolutely  necessary  to  establish  a  definite  limit  of  value 
for  them,  since,  if  every  analyst  selects  another  initial 
substance,  all  possibility  of  comparing  the  analytical  re- 
sults must  of  course  cease.  We  therefore  adhere  through- 
out to  the  term  fine  soil  as  a  designation  for  soil  less  than 
2  millimeters  in  diameter,  and  .take  it  as  the  initial  mate- 
rial for  analysis,  as  has  for  a  number  of  years  been  cus- 
tomary in  the  laboratory  for  soil  analysis  in  the  Royal 
Prussian  Geological  Institute. 
3 


34  THE   EXAMINATION   OF  SOILS. 

The  fine  soil  which  has  passed  through  the  2-milli- 
meter sieve  is  thoroughly  mixed  and  30  to  100  grammes 
of  it  taken  for  silt  analysis. 

The  residue  remaining  after  the  silt  analysis,  with 
an  elutriating  velocity  of  25  millimeters,  is  dried  and 
weighed  and  then  further  granulated  by  passing  through 
sieves  with  holes  1  and  0.5  millimeter  in  diameter. 

B.  Silt  analysis. — The  object  of  silt  analysis  is  to  sepa- 
rate the  fine  soil  obtained  in  the  above-described  manner 
into  still  finer  products  of  granulation. 

The  principle  adopted  in  the  apparatus  used  for 
this  purpose  is  either  to  separate  the  coarser  from  the 
finer  particles  by  their  different  subsiding  velocities  in 
water  at  rest  (decanting  apparatus),  or  to  effect  separa- 
tion by  an  ascending  jet  of  water  (rinsing  or  elutriating 
apparatus). 

To  the  former  class  of  apparatus  belong  :  1.  Bennig- 
sen's  elutriating  flask ;  2.  Knop's  elutriating  cylinder ; 
and  3.  Julius  Kuehn's  elutriating  cylinder ;  and  to  the 
latter  class  the  elutriating  apparatuses  of  Noebel,  Schoene, 
and  Hilgard. 

Of  these  apparatuses  only  Schoene's  and  Hilgard's 
yield  sufficiently  reliable  results.  However,  as  Noebel's 
apparatus  is  occasionally  used,  it  shall  also  be  briefly  de- 
scribed. 

1.  Noebel' s  elutriating  apparatus. — This  apparatus, 
Fig.  1,  consists  of  a  water  reservoir  of  10  liters'  capa- 
city and  four  pear-shaped  vessels,  whose  volumes  are 
as  1  :  8  :  27  :  64  =  I3  :  23  :  33  :  43,  and  which  are  con- 
nected with  each  other  by  knee-shaped  tubes.  The  last 
small  vessel  is  connected  with  the  water  reservoir  by 


ME(  -HAXICAL   SOIL-ANALYSIS. 


35 


means  of  a  rubber  tube  provided  with  a  clip.  The 
largest  vessel  in  front  is  provided  with  a  discharge 
tube,  the  point  of  which  is  drawn  out,  so  that  when 
the  apparatus  is  filled  with  water  9  liters  run  out  in 

Fig.  l. 


40  minutes.  The  water  reservoir  is  provided  with  a 
gauge,  A,  so  that  elutriation  may  be  carried  on  with 
a  constant  pressure  by  connecting  the  tube,  a,  with  a 
water  reservoir  located  at  a  higher  level. 

Fifty  grammes  of  the  soil  to  be  elutriated  (which,  by 
agreement,  is  to  be  less  than  1  millimeter  in  diameter) 
are  prepared  by  boiling  with  water,  and  are  then  rinsed 
into  the  second  smallest  vessel,  6,  the  smallest  vessel 
being  filled  with  water  only.  The  two  larger  vessels 
are  then  filled  to  the  brim  with  water,  and  after  con- 
necting the  entire  system  by  the  connecting  tubes  the 
clip  is  opened  and  the  water  allowed  to  flow  for  40 


36  THE   EXAMINATION   OF   SOILS. 

minutes  through  the  apparatus.    The  following  products 
of  elutriation  are  obtained  by  this  operation  : — 

1.  The  residue  in  vessel  II. 

2.  The  residue  in  vessel  III. 

3.  The  residue  in  vessel  IV. 

4.  The  particles  of  soil  elutriated  from  vessel  IV. 

By  now  evaporating  the  residues  in  vessels  II.,  III., 
and  IV.  in  small,  weighed  porcelain  dishes  and  then 
weighing  them,  the  finest  elutriated  parts  are  obtained 
from  the  difference. 

Noebel's  apparatus,  with  its  four  vessels  of  ever-vary- 
ing capacity  and  slope  of  sides  and  variable  head  of 
pressure,  has  many  defects.  Not  one  of  the  sediments 
obtainable  by  its  use  is  ever  of  a  character  approaching 
uniformity,  and  even  in  one  and  the  same  instrument 
successive  analyses  of  one  and  the  same  material  differ 
widely  in  their  results. 

2.  Schoene's  elutriating  apparatus. — Like  Noebel's, 
this  also  is  a  rinsing  apparatus,  a  current  of  water 
regulated  by  a  stop-cock  and  rising  vertically  in  the 
elutriating  space  being  also  used.  The  water  comes 
from  a  reservoir  standing  at  a  higher  level. 

Whilst  in  the  elutriating  process,  by  means  of  decan- 
tation,  the  gravity  retarded  by  the  fall  in  water  is  made 
use  of  in  Schoene's  as  well  as  in  Noebel's  apparatus,  an 
impelling  force  of  the  waters  upwards,  acting  counter 
to  the  gravity,  is  employed.  Hence,  in  Schoene's  ap- 
paratus, by  velocity  of  elutriation  is  understood  the  space 
through  which  a  particle  of  soil  is  lifted  in  one  second. 
The  length  of  this  space  is  dependent  on  the  volume- 
content  of  the  elutriating  vessel,  the  cross-section  and 


MECHANICAL  SOIL-ANALYSIS. 


37 


specific  gravity  of  the  particle  of  soil,  as  well  as  on  the 
velocity  of  the  ascending  current  of  water. 

Schoene's  elutriator,  Fig.  2,  consists  of  a  glass  vessel, 
the  upper  portion,  B,  of  which  must  be  perfectly 
cylindrical  and  at  least  10  centimeters 
long,  so  that  during  elutriation  an  en- 
tirely uniform  velocity  of  current  pre- 
vails, at  least,  in.  the  upper  portion. 
Its  clear  diameter  should  be,  according 
to  Schoene,  5  centimeters,  as  accurately 
as  possible.  In  order  to  accurately  fix  < 
still  smaller  velocities,  this  diameter 
should  not  be  less  than  4  centimeters. 
The  cylindrical  portion  is  joined  by  the 
very  gradually  tapering  portion  (7, 
which  is  50  centimeters  long.  Below 
the  portion  C  passes  into  a  tube  D  E 
the  clear  diameter  of  which  should, 
under  no  conditions,  be  more  than  5 
millimeters,  and  not  less  than  4  milli- 
meters. This  tube  is  bent  semicircularly 
and  extended  upwards  in  a  vertical 
direction.  Above  the  cylindrical  space 
the  apparatus  has  a  shoulder,  and  passes 
into  the  neck  A,  which  serves  for  the 
reception  of  a  perforated  rubber  cork. 
The  neck  is  2  centimeters  long,  with  a 
diameter  of  1.5  to  2  centimeters. 

A  piezometer,  which  serves  as  an  indicator  of  the  cur- 
rent velocity,  is  pushed  through  the  rubber  cork.  It  has 
a  clear  diameter  of  3  millimeters,  and,  at  a  point  8  centi- 
meters above  its  lower  end,  is  bent  twice  in  the  form  of 


405785 


38  THE   EXAMINATION   OF   SOILS. 

a  knee  at  an  angle  of  45°.  In  the  zenith  of  the  second 
bend  is  a  circular  discharge-aperture,  the  edges  of  which 
should  be  as  smooth  as  possible.  From  1  to  10  centi- 
meters the  piezometer  is  graduated  into  millimeters,  from 
10  to  15  centimeters  into  half  centimeters,  and  above 
that  into  whole  centimeters. 

In  order  that  the  current  of  water,  which  is  regulated 
by  a  stop-cock,  may  remain  as  constant  as  possible,  it  is 
necessary  to  use  as  a  reservoir  a  capacious  shallow  box 
of  zinc  with  a  capacity  of  50  liters,  in  which  the  level 
undergoes  but  little  change  during  elutriation. 

The  arrangement  shown  in  Fig.  3  is  very  suitable 
for  the  elutriating  process. 

The  table  C  serves  for  securing  the  elutriators,  and  is 
71  centimeters  high,  50  centimeters  wide,  and  85  cen- 
timeters long.  Its  top  consists  of  lath-work.  The 
elutriators  are  inserted  between  the  laths  and  screwed 
into  the  joints  of  a  stand  provided  with  a  heavy  cast- 
iron  plate.  To  render  it  more  secure  the  plate  of  the 
stand  is  by  means  of  a  binding  screw  fastened  to  the 
table.  The  latter  also  carries  a  wooden  frame,  G,  140 
centimeters  high,  which,  on  the  top,  is  provided  with 
two  shiftable  coupling  boxes  for  the  support  of  the 
piezometer  tubes.  The  water  reservoir  F  is  provided 
with  a  glass  gauge  and  stands  upon  a  board  secured  by 
cramp  irons.  The  inlet  pipes  E,  screwed  in  the  bottom 
of  the  reservoir  and  provided  with  brass  cocks,  D, 
are  connected  by  means  of  rubber  tubing  with  the 
elutriators. 

The  elutriating  velocity  in  the  cylindrical  space  of 
Schoene's  elutriator  (Fig.  2  J5)  with  a  determined  head 
of  pressure  is  dependent  on  the  cross  section  of  the 


MECHANICAL   SOIL-ANALYSIS. 
Fig.  3. 


39 


40  THE   EXAMINATION   OF   SOILS. 

cylinder  and  the  size  of  the  discharge  aperture  on  the 
piezometer.  Hence  it  is  necessary  first  accurately  to  de- 
termine the  diameter  of  the  cylindrical  elutriating  space. 
For  this  purpose  graduate  the  cylinder  by  pasting  strips 
of  paper  on  the  outside.  A  plane  laid  through  the 
upper  edge  of  the  two  strips  of  paper  should  stand  as 
perpendicular  as  possible  to  the  axis  of  the  cylinder ; 
the  distance  of  the  two  strips  of  paper  from  each  other 
should  be  10  centimeters.  Now  fill  the  entire  cylinder 
with  water,  close  the  end  of  the  tube  E  with  a  cork,  so 
that  no  air-bubbles  remain  therein,  and  let  the  lower 
meniscus  of  the  water  in  the  cylindrical  space  sit  upon 
the  upper  edge  of  the  uppermost  strip  of  paper,  whereby 
the  axis  of  the  cylinder  should  stand  as  perpendicular 
as  possible.  Now,  by  means  of  a  pipette,  remove  the 
water  from  the  cylinder  to  the  upper  edge  of  the  lower 
strip  of  paper,  and  bring  it  into  a  measuring  vessel 
graduated  into  cubic  millimeters. 

The  content  of  a  cylinder  (/),  as  is  well  known,  is 
equal  to  the  product  of  the  base  (r2*)  and  the  altitude 
(h). 

J  =  r2*.  h 


Now  since  the  cross  section  of  the  cylindrical  portion 
of  the  elutriator  is  known,  the  water  is  put  at  a  de- 
termined height  into  the  piezometer  and  a  measuring 
flask,  for  instance,  a  liter,  is  allowed  to  run  full,  the 
number  of  seconds,  t,  required  to  fill  the  flask  being  noted 


MECHANICAL   SOIL-ANALYSIS.  41 

by  a  stop-watch.  The  quantity  (Q)  which  flows  out  in 
a  second  is  then  :  — 

Q  =  x  mm3 
i 

The  elutriating  velocity  is  obtained  by  dividing  the 
number  of  cubic-millimeters,  which  have  not  run  out  in 
one  second,  by  the  cross  section  of  the  cylinder  in  square 
millimeters  (K)  :  — 


r>«    =     Q 
K 

If  a  definitely  determined  elutriating  velocity  is  desired, 
commence  first  at  a  higher  point  of  the  piezometer, 
calculate  the  velocity  from  the  quantity  discharged  in 
one  second,  and  note  whether  it  approaches  the  desired 
velocity  or  not.  According  to  the  result,  commence  the 
next  experiment  at  a  higher  or  lower  mark  of  the  piezo- 
meter. 

With  the  use  of  very  slight  elutriating  velocities,  the 
thread  of  water  does  not  appear  at  a  fixed  mark,  only 
a  dripping  of  the  fluid  taking  place  on  the  discharge 
aperture  of  the  piezometer.  In  this  case,  the  point  to 
which  the  meniscus  of  the  thread  of  water  in  the  piezo- 
meter sinks  in  dripping  off  is  taken  as  the  mark,  the 
number  of  drops  running  off  in  one  minute  being  also 
counted.  For  calculating  the  quantity  discharged  in 
one  second,  it  suffices  to  allow  a  measuring  flask  of  100 
cubic-centimeters  capacity  to  run  full.  By  a  few  experi- 
ments, in  which  the  water-level  in  the  piezometer  is  so 
regulated  that  the  mean  between  the  two  last  determined 


42  THE   EXAMINATION   OF   SOILS. 

limits  is  always  taken,  the  water-level  corresponding  to 
the  elutriating  velocity  sought  is  readily  obtained. 

Instead  of  this  empirical  manner  of  finding  a  de- 
termined elutriating  velocity,  it  can  also  be  calculated  by 
taking  the  piezometer  graduated  into  centimeters  as  a 
basis. 

According  to  the  theoretical  law  of  discharge,  the 
quantities  of  discharge  with  one  and  the  same  piezometer, 
and  hence,  for  one  and  the  same  discharge  aperture,  are 
as  the  square  roots  from  the  heads  of  pressure  in  the 
piezometer.  If,  now,  the  heads  of  pressure  are  indicated 
by  hj  and  kjl}  and  the  quantities  of  discharge  in  one  sec- 
ond by  2t  and  2n,  the  result  will  be  the  equation  :  — 


AH       2n2  (No.  1.) 

In  the  case  in  question  the  law  of  discharge  has  to  be 
somewhat  modified,  as  the  water-level  in  the  piezometer 
is  influenced  by  the  capillary  attraction  in  the  narrow 
tube  of  the  piezometer,  as  well  as  by  the  resistance  the 
water  meets  with  in  running  from  the  narrow  discharge 
aperture.  Hence  to  eliminate  these  influences,  a  constant 
magnitude,  C,  to  be  empirically  determined  for  all  heads 
of  pressure  of  the  same  piezometer,  must,  according  to 
Schoene's  experiments,  be  deducted  from  the  observed 
head  of  water  h.  Thereby,  equation  No.  1  is  modified 
as  follows  :  — 

ftt  .  -  Q  ^  2* 

AII_C"2n«  (No.  2.) 

For  the  determination  of  the  constant  magnitude,  (7,  it 
suffices  to  execute  two  experiments  by  once  allowing  a 


MECHANICAL,  SOIL-ANALYSIS.  43 

liter  to  run  full  at  as  low  a  head  of  pressure  (2  to  3  centi- 
meters), and  then  at  as  high  a  head  of  pressure  (80  to 
100  centimeters)  as  possible,  noting  the  number  of  seconds 
and  calculating  the  quantity  discharged  in  one  second. 
By  inserting  the  data  obtained  in  formula  No.  2,  the  fol- 
lowing formula  results : — 

2IUII—21I.ft1  centimeterg  (N     3  v 

2I'-2II' 

The  constant  magnitude  C  having  thus  been  found, 
the  corresponding  quantities  of  discharge,  Qn,  can  be 
calculated  for  all  desired  heads  of  pressure,  or,  also,  the 
corresponding  heads  of  pressure  for  all  desired  quantities 
of  discharge. 

From  formula  No.  3  result : — 

, Q 

Qn  =  y  fin — C.      /  r — ^  cubic-centimeters    (No.  4.) 

hn  -  Qn\  J^-C      c  centimeters          /No<  g  v 

Q2 

Since  the  quantities  of  discharge  in  one  second  Q,  also 
flow  in  the  same  time  through  any  cross  section  of  the 
elutriating  space  whose  diameter  is  _D,  it  follows  that  if 
i-  designates  the  elutriating  velocity  in  one  second : — 

^ e        j  D2  centimeters  (No.  6.) 

v  =  0     4 

*' centimeters  (No.  7.) 

*D2 

Hence  when  the  constant  magnitude  C  has  been  de- 
termined by  experiments  and  the  velocity  v,  in  the 
elutriating  space  at  a  determined  head  of  pressure  h  is 


44  THE   EXAMINATION   OF   SOILS. 

known,  it  can  be  readily  calculated  what  head  of  water, 
hn,  has  to  be  used,  in  order  to  obtain  the  velocity,  vn, 
sought.  It  is  only  necessary  in  this  case  to  insert  the 
value  for  Q  from  formula  No.  6,  and  the  corresponding 

value  for  Qn  =  vn  —  D2  in  formula  ~No.  5,  whereby  is 
obtained 

,          fvn  rt  -D2^  *        n  .    n         2  A  —  C  , 

/m  =  /  2  h  —  C  -f  C  =  v  —     —  —  \-  C 

4 


(No.  8.) 

With  an  approximately  equal  specific  gravity  and 
globular  form  of  the  material  determined  sizes  of  grains 
correspond  to  determined  velocities.  By  experiments, 
Schoene  has  determined  that  with  quartz  sand  in  globular 
form  and  elutriating  velocities  of  from  0.1  to  12  milli- 
meters per  second,  the  following  relation  exists  between 
the  diameter  of  the  grains  d  and  the  elutriating  velocity 

v  :  — 

7 

d  =  0.0314  v  —  millimeters. 
11 

From  his  calculations,  controlled  by  microscopical 
measurements,  it  follows  that  starting  from  quartz  in 
globular  form,  the  annexed  products  of  granulation  cor- 
respond to  the  following  elutriating  velocities:  — 

0.2  millimeter  of  elutriating  velocity  =  grain  less  than  0.01  millim. 
2.0  millimeters  "  "         =     "     from  0.05  to  0.01   " 

7.0  "  "  "        =     "         "    0.1    toO.05   " 

Since,  on  account  of  the  narrowness  of  the  discharge 
aperture  in  the  piezometer,  a  velocity  of  7  millimeters 
can  only  be  obtained  by  the  introduction  of  a  second 


MECHANICAL   SOIL-ANALYSIS.  45 

piezometer  with  a  wider  discharge  aperture,  Orth  has 
proposed  the  insertion  of  a  small  auxiliary  cylinder 
2.5  centimeters  in  diameter.  Its  cylindrical  portion 
should  be  50  centimeters  long,  so  that  it  can  also  be  used 
for  a  velocity  of  25  millimeters. 

Since  the  production  of  an  accurate  sieve  with  holes 
0.2  millimeter  in  diameter  is  very  difficult  and  expen- 
sive, and  the  sifting  of  the  soil  through  such  a  sieve  does 
not  yield  good  results  on  account  of  the  holes  readily 
clogging  up,  Laufer's  proposition  to  obtain  the  size  of 
grains  from  0.2  to  0.1  millimeter  by  elutriation  may  be 
recommended.  For  this  purpose  Orth's  auxiliary 
cylinder  is  used ;  a  piezometer  about  5  millimeters  in 
diameter  and  with  a  discharge  aperture  of  from  3  to  3.5 
millimeters  being  placed  upon  it.  The  cross-section  of 
the  cylinder  is  determined  in  the  previously  described 
manner,  and,  in  order  to  find  the  velocity  of  25  milli- 
meters which  corresponds  to  the  size  of  grains  0.2  to  0.1 
millimeters  in  diameter,  the  quantities  discharged  at  dif- 
ferent marks  of  the  piezometer  are  measured.  When 
the  desired  velocities  in  the  various  elutriators  have  been 
determined,  a  table  is  made  according  to  the  following 
scheme,  which  is  used  for  all  analyses  to  be  executed 
with  the  apparatus  : — 


46 


THE   EXAMINATION   OF  SOILS. 


Large  elutriator. 

Small  elutriator. 

Diameter         :    mm. 
Cross  section  :    mm9. 

Diameter         :    mm. 
Cross  section  :    mm2. 

Head  of  water  in 
the  narrow  piezo- 
meter, cm. 

Velocity  in  one 
second. 

Head  of  water  in 
the  narrow  piezo- 
meter, cm. 

Velocity  in  one 
second. 

0.2  mm. 

2.0  mm. 

7.0  mm. 

Head  of  water  in 
the  wide  piezo- 
meter, cm. 

25.0  mm. 

For  the  execution  of  an  analysis,  the  air-dried  fine  soil 
passed  through  the  2-millimeter  sieve  is  used.  Spread 
the  soil  upon  a  sheet  of  paper  and  weigh  out  an  average 
sample  of  exactly  100  grammes.  Of  very  uniformly 
and  finely  divided  soils,  30  to  40  grammes  suffice  for 
the  analysis. 

Bring  the  quantity  of  soil,  weighed  out,  into  a  porce- 
lain or  enamelled  iron  dish,  pour  distilled  water  over  it 
and  boil  it,  with  constant  stirring  with  a  glass  rod,  until 
the  clayey  constituents  are  entirely  dissolved.  With 
tenacious  clay  soils,  small  nodules  of  clay  frequently  re- 
main behind  which  do  not  dissolve  even  with  continued 
boiling ;  and  it  is  best  to  crush  them  with  the  index-finger, 
which  for  the  purpose  should  be  protected  with  a  thick 
rubber  coating.  The  material  thus  prepared  is  permitted 
to  become  cold,  when,  without  stirring  up  the  sediment, 
the  supernatant  turbid  fluid  is  poured  into  the  large 
elutriator  of  the  apparatus.  Now,  by  opening  the  stop- 


MECHANICAL   SOIL-ANALYSIS.  47 

cock,  fill  the  small  elutriator  before  connecting  it  with 
the  larger  elutriator,  with  water  up  to  above  the  semi- 
circular lower  bend.  The  purpose  of  this  is,  on  the  one 
hand,  to  prevent  the  apparatus  from  becoming  clogged, 
when  introducing  the  soil,  by  the  latter  ascending  in  the 
narrow  tube,  and,  on  the  other,  to  avoid  mistakes  in  the 
commencement  of  the  elutriating  process  by  ascending  air 
bubbles.  For  the  introduction  of  the  soil  into  the  small 
elutriator,  it  is  best  to  place  upon  the  latter  a  wide- 
mouthed  funnel  and  inject  the  material  with  the  assist- 
ance of  a  wash  bottle.  Detach  any  adhering  particles 
by  means  of  a  glass  rod,  the  lower  end  of  which  is 
covered  with  a  piece  of  rubber  tubing. 

If  it  is  intended  to  make  further  chemical  investiga- 
tions with  the  products  of  elutriation  at  0.2  and  2  milli- 
meters velocity,  the  soil  has  to  be  elutriated  with  distilled 
water.  This  is  necessary,  because  in  gaining  the  product 
of  elutriation  at  0.2  millimeter  velocity,  the  elutriating 
water  has  to  be  evaporated,  and,  by  the  use  of  ordinary 
water,  too  many  impurities  would  be  introduced  into  the 
material  under  investigation.  The  product  of  elutria- 
tion at  0.2  millimeter  velocity  can  only  be  elutriated 
with  ordinary  water,  if  it  is  not  to  be  weighed,  but  to  be 
calculated  from  the  loss, 

For  elutriation  with  distilled  water  it  is  best  to  use 
the  apparatus  shown  in  Fig.  4.  A  glass  tube,  d,  reaching 
to  the  bottom  of  a  glass  balloon,  J,  filled  with  distilled 
water,  connects  with  a  glass  flask,  B,  of  about  10  liters 
capacity.  Near  the  top  of  the  tube  d  is  inserted  a  glass 
tube  provided  with  the  glass  stop-cock,  a.  The  rubber 
cork  of  the  flask  B  is  provided  with  two  other  perfora- 
tions, in  one  of  which  is  inserted,  even  with  the  under 


48 


THE   EXAMINATION   OF   SOILS. 


side  of  the  cork,  the  knee-shaped  glass  tube  g,  which  is 
connected  by  means  of  a  rubber  tube  with  the  lead  tube 
c.  The  latter  is  connected  with  a  small  water  air-pump 
so  that  a  rarefied  space  can  be  created  in  B.  Through 
the  third  perforation  in  the  rubber  cork  passes  a  siphon, 
h,  reaching  to  the  bottom  of  the  flask,  the  long  leg  of 
which  is  provided  below  with  a  glass  stop-cock,  6.  This 

Fig.  4. 


siphon  h  passes  into  one  of  the  tubulures  of  the  glass 
flask  C  standing  at  a  lower  level,  while  the  other  tubulure 
serves  for  the  reception  of  the  water-gauge  D,  through 
the  bottom  of  which  passes  the  tube  e,  which  effects  the 
constant  level  of  the  water.  On  each  side,  near  the  bot- 
tom, the  gauge  D  is  provided  with  a  tubulure,  one  serv- 


MECHANICAL   SOIL-ANALYSIS.  49 

ing  to  connect  the  gauge  with  the  flask  C,  while  the 
other,  by  means  of  a  rubber  tube  and  an  inserted  tube 
provided  with  a  glass  stop-cock,  /,  communicates  with 
the  two  elutriators.  When  the  flask  B  is  to  be  filled, 
the  stop-cocks  a  and  b  are  closed,  and  after  putting  the 
air-pump  in  action,  it  is  connected  with  the  tube  c.  In 
consequence  of  this  a  rarefied  space  is  formed  in  B,  and 
the  water  will  ascend  from  the  balloon  through  the  tube 
<1  and  fill  B.  Now,  in  order  to  have  a  constant  level 
while  elutriating,  the  flask  B  is  filled,  the  stop-cocks  a 
and  b  are  opened,  and  approximately  as  much  water  is 
allowed  to  flow  into  Cas  in  elutriating  flows  out  of  this 
vessel.  The  water  discharged  from  the  gauge-pipe  e 
may  be  caught  and  poured  back  into  the  balloon. 

After  the  soil  has,  in  the  manner  previously  mentioned, 
been  introduced  into  the  small  elutriator,  the  stop-cock,, 
/,  which  serves  for  regulating  the  current  of  water,  i& 
opened  a  little  and  the  operation  commenced  at  the  mark 
on  the  piezometer  tube  corresponding  to  the  lowest 
elutriating  velocity  of  0.2  millimeters.  Two  or  three 
liters  are  first  allowed  to  run  off,  and,  in  case  the  product 
of  elutriation  is  to  be  gained,  evaporated  in  a  large 
porcelain  dish  upon  the  water  bath.  In  this  manner 
one  is  sure  to  obtain  all  the  soil  constituents  soluble  in 
water.  If,  after  running  off  two  or  three  liters,  the 
water  in  the  elutriating  space  of  the  large  elutriator  has 
not  become  entirely  clear,  elutriation  is  continued  at  the 
same  velocity,  without  interrupting  the  operation,  until 
nearly  complete  clarification  takes  place  in  the  upper 
portion  of  the  elutriating  space.  The  elutriating  water 
thus  obtained  is  brought  into  a  large  porcelain  dish  and 
heated  to  boiling.  By  continued  boiling  the  suspended 


50  THE   EXAMINATION   OF   SOILS. 

particles  of  clay  ball  together  and  settle  on  the  bottom, 
so  that,  after  cooling  and  standing  for  some  time,  the 
supernatant,  nearly  clear  water  may  be  siphoned  off  and 
thrown  away.  The  sediment  is  added  to  the  product  of 
elutriation  first  obtained. 

In  many  cases  the  further  elutriating  process  may  be 
continued  with  ordinary  water,  the  remaining  products 
of  elutriation  depositing  readily  so  that  the  supernatant 
water  can  almost  be  entirely  siphoned  off.  The  product 
of  elutriation  is  then  several  times  washed  with  distilled 
water,  and,  after  allowing  the  sediment  to  settle,  the 
water  is  siphoned  off. 

The  velocity  next  to  be  used  is  dependent  on  the  pro- 
portion of  the  cross-sections  of  the  two  elutriators.  If 
the  velocity  of  7  millimeters  appears  in  the  small 
elutriator  at  a  greater  height  of  the  piezometer  than  the 
velocity  of  2  millimeters  in  the  large  elutriator,  com- 
mence first  at  the  height  of  the  piezometer  at  which  a 
velocity  of  2  millimeters  prevails  in  the  large  elutriator. 
In  the  reverse  case,  first  elutriate  with  a  velocity  of  7 
millimeters  in  the  small  elutriator,  and,  only  after  dis- 
engaging the  latter,  set  the  piezometer  so  as  to  obtain  a 
velocity  of  2  millimeters  in  the  large  elutriator. 

The  products  of  elutriation  are  caught  in  large  cylin- 
drical glass  vessels  (A,  Fig.  3)  having  a  capacity  of 
from  10  to  15  liters.  After,  with  a  velocity  of  7.0  milli- 
meters, clarification  has  taken  place  in  the  small 
elutriator,  the  wide  piezometer  (compare  p.  45)  is  placed 
upon  the  small  elutriator  and  elutriation  continued 
with  25  millimeters  velocity  until  clarification  is  com- 
plete. 

By  the  elutriating  process  the  following  products  have 


MECHANICAL   SOIL-ANALYSIS.  51 

been    obtained    (compare   the   numbers   in   the    table. 
p.S2):- 

,/ry.   S.s  Product  of  elutriation  at  0.2  millimeter  velocity.  Discharge.     "O""6 

"  "  2.0          "  "  "  ~en> 


"  "  7.0         "  »  Residue  in  the 

large  elutria- 
tor  (eventual- 
ly also  partial 
discharge). 

"  "  25.0          "  "  Discharge. 

1  4.  Residue  "  25.0          "  "  Residue  in  the 

small  elutria- 
tor. 

The  two  residues  (6  and  4)  are  best  removed  from  the 
elutriators  by  connecting  the  latter  with  the  water  reser- 
voir, then  inverting  them  in  a  large  dish,  and,  after 
opening  the  cock,  rinsing  out  their  contents. 

The  supernatant  clear  water  is  next  siphoned  off,  when 
the  products  of  elutriation  are  brought  into  small 
previously  weighed  porcelain  dishes  with  flat  bottoms 
and  for  some  time  dried  in  a  sand  bath  heated  to  about 
212°  F.  After  cooling,  the  dishes,  before  being  weighed, 
are  allowed  to  stand  at  least  one  or  two  days  so  that  the 
products  of  elutriation  may  re-acquire  the  content  of 
moisture  of  the  air  of  the  room. 

The  products  obtained  by  granulation  and  elutriation 
are  centesimally  calculated  for  the  entire  soil,  and  the 
figures  entered  in  the  following  scheme  :  — 


52 


THE   EXAMINATION   OF   SOILS. 


Clayey  parts. 

Gravel 

Sand. 

Total. 

more 

Dust. 

Finest. 

than 

2  mm  in 
diameter. 

2  to 

1  to 

0.5  to 

0.2  to 

0.1  to 

0.05  to 

less  than 

1  mm. 

0.5  mm. 

0.2  ram. 

0.1  mm. 

0.05  mm. 

0.01  mm. 

0.01  mm. 

2.4 

71.0 

26.7 

100.1 

2.0 

3.6 

16.0 

32.3 

17.1 

12.4 

14.3 

Mistakes  in  elutriating  with  Schcene's  apparatus  are 
avoided  by  executing  the  process  as  uninterruptedly  and 
uniformly  as  possible.  Numerous  experiments  have 
shown  that  the  method  yields  sufficiently  accurate 
results. 

3.  Hilgard's  elutriating  apparatus. — To  avoid  mis- 
takes arising  from  flocculent  aggregates  of  the  finest 
particles  of  soil,  Prof.  E.  W.  Hilgard  has  proposed*  the 
elutriating  apparatus  shown  at  Fig.  5.  He  uses  a 
cylindrical  elutriating  tube,  T,  of  34.8  millimeters  inside 
diameter  at  its  mouth,  and  290  millimeters  high.  At- 
tached to  its  base  is  a  rotary  churn,  P,  consisting  of  a 
porcelain  beaker  triply  perforated,  viz.,  at  the  bottom 
for  connection  with  the  relay  reservoir,  R ;  and  at  the 
sides  for  the  passage  of  a  horizontal  axis,  A,  bearing  four 
grated  wings.  This  axis,  of  course,  passes  through  stuffing 
boxes  firmly  cemented  to  the  roughened  outside  of  the 
beaker  and  provided  with  good  thick  leather  washers, 
saturated  with  tallow.  These  washers,  if  the  axes  run 
true,  will  bear  a  million  or  more  of  revolutions  without 


*   E.   W.    Hilgard.     Silt   Analysis   of  Soils    and   Clays.     Am. 
Journal  of  Science  and  Arts,  vol.  VI.,  October,  1873. 


MECHANICAL  SOIL-ANALYSIS. 


53 


material  leakage.  From  500  to  600  revolutions  per 
minute  is  a  proper  velocity,  which  may  be  imparted  by 
clock-work  or  a  turbine. 

As  the  whirling  agitation  caused  by  the  rotation  of 
the  dasher  would  gradually  communicate  itself  to  the 
whole  column  of  water,  and  cause  irregularities,  a  (pre- 


Fig.  5. 


-c 


ferably  concave)  wire  screen  of  0.8  millimeter  aperture 
is  cemented  to  the  lower  end  of  the  cylinder.  No 
irregular  currents  are  then  observed  beyond  about  75 
millimeters  above  the  screen,  whose  meshes  are  yet 
sufficiently  wide  to  allow  any  heavy  particles  or  aggre- 
gates to  sink  down  freely.  Any  grains  too  coarse  to  pass 
must,  however,  be  previously  sifted  out. 


54  THE   EXAMINATION   OF  SOILS. 

Thus  arranged,  the  instrument  works  quite  satis- 
factorily ;  and  by  its  aid,  soils  and  clays  may  readily  be 
separated  into  sediments  of  any  hydraulic  value  desired. 
But  in  order  to  insure  correct  and  concordant*  results, 
it  is  necessary  to  observe  some  precautions,  to  wit : — 

1.  The  tube  of  the  instrument  must  be  as  nearly 
cylindrical  as  possible,  and  must  be  placed  and  main- 
tained in  a  truly  vertical  position.     A  very  slight  devia- 
tion from  the  vertical  at  once  causes  the  formation  of 
return  currents,  and  hence  of  molecular  aggregates  on 
the  lower  side. 

2.  Sunshine,  or  the  proximity  of  any  other  source  of 
heat,  must  be  carefully  excluded.     The  currents  formed 
when  the  instrument  is  exposed  to  sunshine  will  com- 
pletely vitiate  the  results. 

3.  The  Mariotte's  bottle  should  be  frequently  cleansed, 
and  the  water  used  be  as  free  from  foreign  matters  as 
possible.     For  ordinary  purposes,  it  is  scarcely  necessary 
to  use  distilled  water ;  the  quantities  used  are  so  large  as 
to  render  it  difficult  to  maintain  an  adequate  supply; 
and  the  errors  resulting  from  the  use  of  any  water  fit 
for  drinking  purposes  are  too  slight  to  be  perceptible,  so 
long  as  no  considerable  development  of  the  animal  and 
vegetable  germs  is  allowed.     Water  containing  the  slimy 
fibrils   of  fungoid  and  moss  prothallia,  vorticellse,  etc. 
will  not  only  cause  errors  by  obstructing  the  stop-cock 
at  low  velocities,  but  these  organisms  will  cause  a  coa- 
lescence of  sediments  that  defies  any  ordinary  churning, 
and  completely  vitiates  the  operation. 

4.  The  amount  of  sediment  discharged  at  any  one 

*  Usually  within  5  per  cent,  of  the  quantities  found. 


MECHANICAL    SOIL-ANALYSIS.  55 

time  must  not  exceed  that  producing  a  moderate  turbidity. 
Whenever  the  discharge  becomes  so  copious  as  to  render 
the  moving  column  opaque,  the  sediments  assume  a 
mixed  character ;  coarse  grains  being,  apparently,  upborne 
by  the  multitude  of  light  ones  whose  hydraulic  value 
lies  considerably  below  the  velocity  used ;  while  the 
churner  also  fails  to  resolve  the  molecular  aggregates 
which  must  be  perpetually  reforming,  where  contact  is 
so  close  and  frequent. 

This  difficulty  is  especially  apt  to  occur  when  too  large 
a  quantity  of  material  has  been  used  for  analysis,  or 
when  one  sediment  constitutes  an  unusually  large  portion 
of  it.  In  either  case,  a  portion  of  the  substance  may  be 
allowed  to  settle  into  the  relay  reservoir  until  the  part 
afloat  in  the  churn  and  tube  is  partly  exhausted ;  after 
which  the  rest  can  be  gradually  brought  up  and  worked 
off.  Or,  the  sediments  shown  by  the  microscope  to  be 
much  mixed,  may  be  worked  over  a  second  time.  Either 
mode,  however,  involves  so  grievous  a  loss  of  time  as  to 
render  it  by  far  preferable  to  so  regulate  the  amount 
employed,  that  even  the  most  copious  sediments  can  be 
worked  off  at  once.  Within  certain  limits,  the  smaller 
the  quantity  employed,  the  more  concordant  are  the 
results.  Between  ten  and  fifteen  grammes  is  the  proper 
amount  for  an  instrument  of  the  dimensions  given 
above. 

It  has  been  found  that,  practically,  0.25  millimeter 
per  second  is  about  the  lowest  velocity  available  within 
reasonable  limits  of  time ;  and  that  by  successively 
doubling  the  velocities  up  to  64  millimeters,  a  desirable 
ascending  series  of  sediments  is  obtained,  provided 
always  that  a  proper  previous  preparation  had  been  given 
to  the  soil  or  clay. 


56  THE   EXAMINATION   OF  SOILS. 

VI. 

DETERMINATION  OF  THE  SOIl^CONSTITUENTS. 

A.  Determination  of  the  content  of  caleium  carbonate 
or  of  magnesium  carbonate. — With  soils  containing  only 
small  quantities  of  magnesium  carbonate,  it  suffices  to 
determine  the  carbonic  acid  expelled  by  stronger  acids, 
and  to  calculate  from  it  the  equivalent  quantity  of  cal- 
cium carbonate. 

The  content  of  calcium  or  magnesium  carbonate  in  a 
soil  is  of  double  significance,  for,  on  the  one  hand, 
they  may  be  present  in  such  large  quantities  as  to  form 
an  important  constituent  of  the  soil,  and,  on  the  other, 
they  play  an  important  role  in  the  nourishing  of  plants, 
even  if  present  in  such  small  quantities  that  they  can  no 
longer  be  classed  as  constituents. 

According  to  the  degree  of  accuracy  aimed  at,  the 
carbonic  acid  may  be  determined  by  three  different 
methods,  viz :  by  volumetric  measurement,  by  weighing 
from  the  loss,  or  by  direct  weighing  a  volumetric  measure- 
ment of  the  carbonic  acid  with  Scheibler's  apparatus. 

a.  Volumetric  measurement  of  the  carbonic  acid  is  made 
use  of  for  strongly  calcareous  soil ;  for  instance,  diluvial 
marls,  meadow  limes,  and  argillaceous  marls,  where  the 
rapid  determination  of  the  approximative  content  of 
calcium  carbonate  in  whole  per  cent,  is  sufficiently 
accurate.  As  the  initial  material  for  this  purpose,  fine 
soil  dried  at  212°  F.  is  used,  and  if  such  is  not  at  hand, 
the  soil  itself.  The  material  is  to  be  quite  finely  pulver- 
ized in  a  cast-steel  mortar. 


DETERMINATION    OF   THE   SOIL-CONSTITUENTS.       57 


Fig.  6. 


Scheibler's  apparatus,  Fig.  6,  is  arranged  as  follows : — 
Two  glass  tubes  28  millimeters  in  diameter  are  vertically 
secured  to  a  wooden  frame.  The  tube  to  the  right  is 
graduated  into  half  and  whole  centimeters  and  holds  about 
300  cubic  centimeters.  Below  both  the  tubes  are  con- 
nected by  a  bent  glass  tube.  The  top  of  the  tube  to  the 
left  is  closed  by  a  cotton  plug.  Near  the  bottom  of  this 
tube  is  a  glass  tube  which  is  bent  upwards  and  connects, 
by  means  of  a  rubber  tube  provided  with  a  clip,  with  an 
open  flask  tubulated  near  the  bottom.  The  rubber  tube 
must  be  of  such  a  length  that  the  flask  may  conveniently  be 
placed  upon  a  board  located  above  the  frame.  The  gradu- 
ated tube  is  connected,  by  means 
of  a  tube  provided  on  the  side 
with  a  glass  cock,  having  a  glass 
bulb  which  receives  the  carbonic 
acid,  so  that  the  latter  cannot  be 
absorbed  by  the  water  in  the 
graduated  tube.  With  the  lower 
end  of  this  glass  bulb  is  con- 
nected, by  means  of  a  rubber 
tube,  the  developing  vessel, 
which  consists  of  a  glass  flask 
with  a  wide  neck,  in  which  accu- 
rately fits  a  rubber  cork  pro- 
vided with  a  tube. 

In  using  the  apparatus  the 
glass  flask  filled  with  water  is 
set  upon  the  board  above,  the 
frame,  and  the  glass  cock  to  the 
right  being  opened,  both  tubes 
are  allowed  to  run  full  to  above 


58  THE    EXAMINATION    OF   SOII.S. 

the  graduation.  The  flask  is  then  taken  down,  and 
by  carefully  opening  the  clip,  water  is  allowed  to  flow 
off  until  the  lower  meniscus  of  the  water  level  in 
the  graduated  tube  sits  exactly  upon  the  0  mark. 
In  both  the  communicating  tubes  the  water  will  be 
at  the  same  level.  In  order  to  have  always  ap- 
proximately the  same  tension  of  aqueous  vapor,  the 
developing  flask  is,  shortly  before  use,  rinsed  out  with 
concentrated  common  salt  solution.  Then  by  means  of 
a  pipette  20  cubic  centimeters  of  hydrochloric  acid  (1 
part  concentrated  hydrochloric  acid  to  3  water)  are 
introduced.  Now  place,  with  the  assistance  of  straight 
crucible-tongs,  a  small  porcelain  crucible  containing 
about  four  to  eight  grammes  of  the  substance  to  be  ex- 
amined in  the  hydrochloric  acid,  and  firmly  put  the 
rubber  cork  into  the  neck  of  the  flask,  without,  however, 
touching  the  developing  space  with  the  warm  hand. 
Now  close  the  glass  cock,  and  by  opening  the  clip  allow 
about  20  cubic  centimeters  of  water  to  run  off,  as  other- 
wise, in  consequence  of  the  violent  evolution  of  carbonic 
acid  in  the  beginning  of  the  operation,  water  would  be 
thrown  from  the  tube  to  the  right.  After  the  discharge 
of  the  20  cubic  centimeters  of  water,  the  level  in  the 
tube  to  the  right  will  be  somewhat  lower,  but  will 
remain  constant  at  one  point.  Should  this  not  be  the 
case,  the  apparatus  leaks  somewhere.  Now,  grasp  with 
the  left  hand  the  clip,  and,  with  the  right  the  develop- 
ing flask  so  that  the  thumb  lies  on  the  left  of  the  neck, 
the  index-finger  upon  the  top  of  the  rubber  cork,  and 
the  middle  finger  on  the  right  of  the  neck.  In  this 
manner  the  vessel  can  be  very  firmly  held,  and  heating 
by  the  hand  is  avoided.  Incline  the  flask  until  the 


DETERMINATION    OF   THE   SOIL-CONSTITUEXTS.       59 

porcelain  crucible  tumbles  over  and  then  impart  a 
circular  motion  to  the  flask.  During  the  evolution  of 
carbonic  acid  a  quantity  of  water,  corresponding  to  the 
sinking  of  the  level  in  the  tube  to  the  right,  is  discharged 
by  opening  the  clip.  Shaking  of  the  developing  vessel 
is  continued  until  the  level  in  the  tube  to  the  right 
remains  constant.  The  apparatus  is  now  allowed  to 
stand  quietly  for  ten  minutes,  then  again  shaken,  and, 
when  the  water  is  at  the  same  level  in  all  the  tubes,  the 
number  of  centimeters  of  carbonic  acid  is  read  off. 
With  due  regard  to  the  temperature  and  the  height  of 
the  barometer,  the  weight  of  the  carbonic  acid  or  of  the 
calcium  carbonate  corresponding  to  it,  is  calculated  to  R. 
Finkener's  tables  (pp.  60  and  61),  in  which  the  weight  of 
a  cubic  centimeter  of  carbonic  acid  at  different  tempera- 
tures and  barometer  heights  is  given  in  one-thousandths 
milligrammes.  In  this  figure  is  included  the  error  arising 
from  measuring  the  gas  in  a  moist  state,  and  from  the 
absorption  of  a  quantity  of  carbonic  acid  by  the  hydro- 
chloric acid  of  the  developing  vessel. 


60 


THE   EXAMINATION   OF   SOILS. 


Thermometer  (Centigrade). 


Barometer. 


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DETERMINATION   OF   THE  SOIL-CONSTITUENTS.      61 


Thermometer  (Centigrade). 


Barometer. 


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62 


THE   EXAMINATION   OP   SOILS. 


b.  Determination  of  the  carbonic  add  by  weighing  from 
the  loss. — This  method  consists  in  expelling,  in  a  weighed 
apparatus,  the  carbonic  acid  by  dilute  acids,  again  weigh- 
ing the  apparatus  and  calculating  the  content  of  carbonic 
acid  in  the  substance  from  the  loss  in 
weight.  An  apparatus  very  suitable 
for  this  purpose  is  Mohr's,  modified  by 
Laufer  and  Wahnschaffe,  Fig.  7.  It 
consists  of  a  small  glass  flask  with  a 
thin  bottom  and  short  wide  neck,  which 
serves  for  the  reception  of  the  sample 
of  soil  to  be  examined.  The  finely  pul- 
verized material  is  dried  by  spreading 
it  out  upon  a  watch  crystal  and  placing 
it  in  a  drying  chamber  heated  to  212° 
F.  for  one  hour.  It  is  then  brought  hot 
into  a  small  glass  tube  also  dried  out  at 
212°  F.,  and  the  latter  closed  with  a 
cork.  After  cooling,  the  tube  together 
with  the  cork  is  weighed,  two  or  three  grammes  of  the 
substance  are  poured  into  the  glass  flask,  and  the  tube 
is  again  weighed.  The  difference  between  the  two 
weighings  corresponds  to  the  weight  of  the  initial  sub- 
stance dried  at  212°  F.  In  the  neck  of  the  glass  flask 
a  hollow  glass  stopper  provided  with  two  tubulures  is  her- 
metically ground  in.  In  the  tubulures  two  glass  tubes  of 
different  forms  are  also  ground  in.  One  tube  is  bent  at  a 
right  angle,  and  then  again  upwards  and  widens  above  the 
second  bend.  It  serves  for  the  reception  of  calcium 
chloride,  and  is  filled  by  first  pushing  in  loosely  a  small 
cotton  plug,  placing  upon  the  latter  a  layer  of  pieces  of 
calcium  chloride  the  size  of  pin-heads,  then  introducing 


DETERMINATION   OF   THE  SOIL-CONSTITUENTS.      63 

another  cotton  plug  and  finally  closing  it  with  the  glass 
stopper  provided  with  two  tubulures.  Over  the  end  of 
the  tube  is  drawn  a  small  piece  of  rubber  tube,  in  the 
top  of  which  a  small  glass  rod  is  pushed.  The  other 
tube  reaches  nearly  to  the  bottom  of  the  vessel,  and  near 
the  top  it  is  provided  with  a  glass  cock  for  the  admission 
of  the  acid  into  the  apparatus.  Above,  the  tube  expands 
pear-shaped  for  the  reception  of  the  acid,  and  is  closed 
in  the  same  manner  as  the  other  tube  by  a  glass  stopper, 
rubber  tube,  and  glass  rod.  The  filling  with  dilute  acid 
(1  part  concentrated  acid  and  10  parts  water)  is  effected 
by  immersing  the  pear-shaped  tube  inverted  in  the  acid, 
and,  with  the  glass  cock  open,  sucking  the  acid  up  until 
the  pear-shaped  receptacle  is  nearly  filled.  The  cock  is 
then  closed,  the  tubulure  dried  with  blotting-paper,  and 
the  rubber  tube  placed  over  it.  Some  distilled  water  is 
poured  over  the  material  in  the  flask.  When  all  the 
tubes  have  been  firmly  placed  in  position,  the  apparatus 
is  wiped  off  with  a  dry  piece  of  leather,  and,  after  stand- 
ing for  half  an  hour,  weighed.  The  rubber  tubes  are 
then  removed,  and  the  acid  is  allowed  to  run,  drop  by 
drop,  into  the  flask.  The  carbonic  acid  having  been  ex- 
pelled, the  bottom  of  the  flask  is  heated  with  a  very 
small  flame  by  placing  the  flask  upon  an  asbestos  plate, 
whereby  the  acid  pipe  must  remain  closed.  After  heat- 
ing nearly  to  boiling,  so  that  the  carbonic  acid  absorbed 
by  the  water  is  expelled,  allow  the  apparatus  to  cool, 
and  then,  in  order  to  remove  all  the  carbonic  acid,  draw 
a  slow  current  of  air  through  the  apparatus  by  connect- 
ing the  calcium  chloride  tube  with  an  aspirator  (E,  Fig. 
8).  Now  close  the  apparatus  with  the  rubber  tubes,  let 
it  stand  for  half  an  hour  in  the  weighing-room,  so  that' 


64  THE   EXAMINATION   OF   SOILS. 

it  again  acquires  the  temperature  of  the  latter;  lift,  be- 
fore weighing,  the  rubber  tube  on  the  calcium  chloride 
tube  for  the  equalization  of  the  air  pressure,  and  weigh 
after  replacing  the  rubber  tube.  By  duly  observing  all 
precautionary  measures  and  paying  special  attention 
that  in  heating,  the  fluid  is  not  brought  to  the  boiling 
point,  the  carbonic  acid  can,  by  this  method,  be  accu- 
rately determined  to  fa  per  cent. 

c.  Determination  of  the  carbonic,  acid  by  direct  weigh- 
ing.— This  mode  of  determination  consists  in  expelling 
the  carbonic  acid  by  hydrochloric  acid  and  catching  it 
in  an  absorption-apparatus  which  can  be  weighed.  This 
method  is  used  whenever  the  carbonic  acid,  even  in  very 
small  quantities,  is  to  be  determined  as  accurately  as 
possible. 

R.  Finkener's  apparatus,  shown  at  Fig.  8,  is  very 
suitable  for  the  purpose.  Of  the  substance  dried  at 
212°  F.,  0.5  to  2  grammes  are  weighed  out  and  brought 
into  a  flask  upon  the  neck,  a,  of  which  sits  a  tube 
secured  to  the  flask  by  two  copper  wire  rings  connected 
by  spirals.  On  one  side  the  tube  has  an  ascending  joint, 
upon  the  end,  c,  of  which  sits  the  calcium  chloride  tube. 
The  latter  is  93  centimeters  long,  and  has  an  ascending 
and  a  descending  leg,  cd  and  de,  the  latter  of  which  is 
only  filled  with  calcium  chloride,  while  the  former  serves 
for  the  reception  and  condensation  of  the  aqueous  vapors 
escaping  in  boiling.  The  calcium  chloride  tube  is  also 
secured  to  the  glass  joint  by  means  of  rings  and  spirals. 
Above  the  glass  joint  is  a  glass  stop-cock,  !>,  and  over 
it  a  funnel  in  the  bottom,  b,  of  which  a  knee-shaped 
tube  is  ground  in.  Below  the  glass  stop-cock  the  funnel 
'tube  narrows  and  reaches  nearly  to  the  bottom  of  the 


DETERMINATION    OF   THE   SOIL-CONSTITUENTS.       65 

flask  where  it  is  bent  upwards,  so  that  during  the  evolu- 
tion of  carbonic  acid  no  bubbles  can  ascend  in  it.  The 
end  of  the  calcium  chloride  tube  is  connected  by  means 
of  rubber  tubing  with  a  small  Geissler  potash-apparatus, 


Fi 


Dy  which  is  more  plainly  shown  in  Fig.  9.  It  is  filled 
with  caustic  potash  solution  (1  part  caustic  potash  to  2 
parts  water).  The  small  wash  bottles  of  this  apparatus 
are  filled  three-quarters  full  by  providing  the  upper  end 
5 


66  THE   EXAMINATION   OF   SOILS. 

of  the  tube  with  a  rubber  tubing  dipping  in  the  caustic 
potash  solution,  and  sucking  with  the  mouth  on  the  tube 
end  of  the  calcium  chloride  tube.  The  wash  bottles 
having  been  filled,  the  rubber  tubing  is  removed  and 
the  tube-end  thoroughly  cleansed  with  blotting-paper. 
The  calcium  chloride  tube  is  then  filled,  and  the  appa- 
ratus, after  having  been  wiped  with  a  piece  of  leather 
and  closed  with  rubber  tubing,  is  placed  for  some  time 
in  the  balance  in  order  to  acquire  the  temperature  of  the 
weighi  ng-room . 

Some  distilled  water  is  then  poured  over  the  material 
in  the  flask,  and  after  inserting  the  glass  tube  bent  at 
a  right  angle  in  the  funnel,  a  current  of  air  previously 
freed  from  its  carbonic  acid  in  a  potash  wash  bottle  (A, 
Fig.  8),  is  conducted  through  the  apparatus.  For  the 
conduction  of  the  air  it  is  best  to  use  a  small  Bunsen 
water  air-pump,  the  current  of  air  being  regulated  by 
inserting  the  apparatus,  E,  seen  in  the  illustration. 
This  apparatus  consists  of  an  ordinary  glass  flask  with 
a  doubly  perforated  rubber  cork.  In  the  cork  sit  two 
glass  tubes,  the  lower  end  of  one  of  which  is  drawn  out 
to  a  fine  point,  and  dips  about  two  centimeters  deep  into 
the  water  in  the  flask.  The  other  tube,  which  is  even 
with  the  lower  surface  of  the  cork,  is  in  direct  communi- 
cation with  the  air-pump,  and  is  provided  with  a  glass 
stop-cock,  the  boring  on  the  mouth  of  which  is  laterally 
indented,  so  that,  even  with  a  strong  air  pressure,  small 
air  bubbles  can,  at  determined  intervals,  be  passed 
through  the  fluid  in  the  flask.  After  sucking  through 
about  three  times  as  much  air  as  the  apparatus  contains, 
the  tube  is  removed  from  the  funnel,  and,  after  closing 
the  glass  stop-cock,  J5,  the  funnel  is  filled  with  dilute 


DETERMINATION   OP   THE   SOIL-CONSTITUENTS.      67 

hydrochloric  acid  (1  part  acid  to  10  parts  water).  The 
weighed  Geissler  potash-apparatus  is  then  connected 
with  the  long  calcium  chloride  tube  and  the  acid  allowed 
to  rim,  drop  by  drop,  into  the  flask.  When  evolution 
has  somewhat  abated,  a  very  small  flame  is  brought 
under  the  apparatus,  while  a  slow  current  of  air  is  passed 
through  it.  The  fluid  is  now  heated  to  just  below  the 
boiling  point,  when  the  flame  is  removed  and  the  current 
of  air  somewhat  augmented.  The  operation  is  finished 
when  three  times  the  volume  of  air  which  the  apparatus 
contains  is  sucked  through  it.  The  potash  apparatus 
closed  at  both  ends  with  rubber  tubing  is  allowed  to 
stand  half  an  hour  in  the  balance  and  is  then  weighed, 
after  being  wiped  with  a  piece  of  leather  and  removing 
the  frictional  electricity  thereby  produced  with  a  metallic 
brush. 

If  metallic  sulphides  are  present  in  the  soil,  which 
are  decomposed  by  the  acid  and  yield  sulphuretted 
hydrogen,  add  first  some  chloride  of  mercury  to  the 
fluid.  If,  with  the  use  of  hydrochloric  acid,  chlorine 
should  be  evolved,  which  may  happen  in  the  presence  of 
oxides  of  manganese,  first  let  some  concentrated  stannous 
chloride  solution  run  into  the  flask. 

After  using  the  apparatus  the  condensed  water  in  the 
ascending  portion  of  the  calcium  chloride  tube  is  re- 
moved by  means  of  a  flame,  and  the  tube  closed  on  both 
ends.  By  this  means  it  can  be  used  for  a  long  time 
without  the  necessity  of  refilling  it. 

d.  Determination  of  the  carbonate  of  calcium  and 
magnesium  by  boiling  with  ammonium  nitrate. — If  it  is 
necessary  to  determine  the  proportion  of  the  carbonates 
of  calcium  and  magnesium,  the  following  method,  first 


68  THE   EXAMINATION    OF   SOILS. 

used  by  E.  Laufer,  can  be  recommended.  Bring  one  or 
two  grammes  of  the  material,  pulverized  as  finely  as 
possible  and  dried  at  212°  F.,  into  a  beaker-glass  and 
pour  20  cubic  centimeters  of  completely  saturated  am- 
monium nitrate  solution  over  them.  After  covering  the 
beaker-glass  with  a  watch  crystal,  boil  the  fluid  for  half 
an  hour,  and,  in  case  the  salt  should  separate  fey  the 
evaporation  of  the  water,  add  some  hot  water.  Am- 
monium nitrate  possesses  the  property  of  converting  the 
carbonates  of  calcium  and  magnesium  into  soluble 
nitrates,  while  the  ammonium  carbonate  formed  thereby 
is  decomposed  by  boiling  and  escapes. 

CaC03  4-  MgC03  4- 
4- 


The  soil  is  then  allowed  to  settle,  and  the  supernatant 
hot  solution  decanted  off  through  a  filter  by  placing  the 
funnel  in  a  copper  hot-water  funnel,  Fig.  10,  heated  to 
212°  F.,  so  that  during  filtration  the  ammonium  nitrate 
cannot  separate  and  clog  up  the  funnel.  The  boiling 
with  the  solution  is  repeated  twice  ;  the  material  in  the 
glass  is  then  washed  with  somewhat  more  dilute  am- 
monium nitrate  solution  and  the  washing  fluid  also 
poured  through  the  filter.  In  case  the  material  is  not  to 
be  further  used,  it  is  unnecessary  to  bring  it  entirely 
upon  the  filter.  Washing  with  pure  distilled  water 
cannot  be  done,  as  otherwise  the  fluid  running  off  is 
rendered  turbid  by  the  fine  particles  of  soil  which  pass 
through  the  filter.  Washing  is  finished  when  a  drop 
running  off  from  the  filter  leaves  no  perceptible  residue 
when  evaporated  upon  a  platinum  sheet. 

The  filtrate  strongly  diluted  with  water  is  heated  to 


DETERMINATION    OF   THE   SOIL-CONSTITUENTS.       69 

boiling,  compounded  with  a  few  drops  of  ammonia  and 
the  lime  precipitated  with  ammonium  oxalate.  After 
standing  for  twelve  hours  the  white  precipitate  of  calcium 


.  10. 


oxalate  has  completely  settled.  The  supernatant  fluid 
is  then  poured  off  through  a  filter ;  the  precipitate  is 
washed  by  several  times  decanting  it  with  hot  water  in 
the  beaker-glass  and  finally  brought  upon  the  filter. 
The  portions  of  the  precipitate  adhering  to  the  glass  are 
removed  with  a  glass  rod  over  the  lower  end  of  which  a 
piece  of  black  rubber  tubing  has  been  drawn.  The 
filter  is  now  washed  out  with  hot  water,  with  the  aid  of 
the  wash  bottle.  The  operation  is  finished  when  a  drop 


70 


THE   EXAMINATION   OF   SOILS. 


running  off  leaves  no  perceptible  residue  when  evaporated 
upon  a  platinum  sheet. 

The  oxalate  of  lime  is  dried  in  the  drying  stove  (Fig. 
12),  at  212°  F.,  then  detached  from  the  filter  and  brought 
into  a  weighed  platinum  crucible,  while  the  filter  is.. 


folded  together  and  incinerated  upon  the  lid  of  the 
crucible.  The  ash  is  then  brought  into  the  platinum 
crucible,  which  is  best  effected  with  the  aid  of  a  pencil, 
and,  after  placing  the  lid  upon  the  crucible,  the  latter  is 
gradually  brought  to  ignition.  In  order  to  completely 
convert  the  calcium  carbonate  formed  by  gentle  igniting 


DETERMINATION   OF   THE   SOIL-CONSTITUENTS.      71 

into  calcium  oxide,  it  is  necessary  to  subject  the  crucible 
for  ten  minutes  to  a  strong  heat  over  a  blast-lamp  (Fig. 
11).  Before  weighing,  cool  the  hot  crucible  and  contents 
in  a  desiccator.  Caustic  lime  being  hygroscopic,  weigh- 
ing must  be  effected  as  rapidly  as  possible.  Generally 
speaking,  it  is  best  to  weigh  all  hygroscopic  substances 
twice,  by  allowing  the  weights  of  the  first  weighing  to 
remain  in  the  pan  of  the  balance,  then  again  heating  the 
crucible  and  its  contents,  and  again  weighing  after  cool- 
ing in  the  desiccator.  Since  the  difference  amounts  at 
the  utmost  to  from  one  to  two  milligrammes,  the  weight 
can  very  rapidly  be  determined  by  two  or  three  oscilla- 
tions of  the  beam  of  the  balance.  To  find  the  corre- 
sponding quantity  of  calcium  carbonate,  multiply  the 
number  of  weighed  grammes  of  calcium  oxide  with  the 
factor  1.786. 

The  filtrate  from  the  lime-precipitate  is  evaporated  to 
about  half  its  volume  in  a  platinum  dish,  then  brought 
into  a  beaker-glass  and  solution  of  sodium  phosphate 
added.  Then  add  concentrated  ammonia  sufficient  to 
amount  to  one-third  of  the  entire  solution.  With  a 
moderate  heat  (77°  to  86°  F.),  a  white  crystalline  pre- 
cipitate consisting  of  ammonium  magnesium  phosphate  = 
POtNgNH4  +  6H20  is  separated  inside  of  twenty-four 
hours.  The  precipitate  is  filtered  off  and  washed  out 
with  a  cold  mixture  of  one  part  of  concentrated  ammonia 
and  three  parts  of  water.  Before  igniting  in  a  porcelain 
crucible,  the  dried  precipitate  is  detached  as  much  as 
possible  from  the  filter,  and  the  latter  incinerated  by 
itself.  Then  add  the  ash  to  the  contents  of  the  crucible 
and  ignite  over  the  blast-lamp.  If,  after  igniting,  the 
precipitate  should  be  colored  gray  or  black  by  uuburnt 


72  THE   EXAMINATION   OF   SOILS. 

coal,  moisten  it  by  allowing  a  drop  of  nitric  acid  to  fall 
upon  it,  place  the  lid  upon  the  crucible  and  heat  the 
latter  gently  at  first,  and,  afterwards,  over  the  blast-lamp. 
By  the  action  of  the  heat  the  ammonium  magnesium 
phosphate  is  transformed  into  magnesium  pyrophosphate 
=  1/(72P207.  Cool  the  crucible  and  contents  in  a  desic- 
cator and  weigh.  The  increase  in  the  weight  of  the 
crucible  represents  the  weight  of  the  magnesia  pyrophos- 
phate; this  multiplied  by  0.757  will  give  the  equivalent 
quantity  of  magnesium  carbonate. 

B.  Determination  of  the  humus  substances. — By  humus 
are  understood  all  the  substances  originating  from  the 
decomposition  of  plant-remains,  in  which  carbon  appears 
in  organic  combination. 

With  a  full  access  of  air  and  at  an  ordinary  tempera- 
ture, plant-remains  are  decomposed  into  a  pale  brown  or 
dark  brown  substance,  which  dissolves  with  a  brown 
color  in  alkalies  and  forms  alkaline  humates.  The  re- 
action of  this  humus  is  neutral. 

If  the  decomposition  of  the  plant-remains  takes  place 
under  water,  hence,  without  the  access  of  air,  a  gray- 
black  mass  is  formed,  which  in  a  fresh  state  is  muddy, 
but  in  a  dry  state  pulverulent.  On  account  of  its  acid 
reaction  this  mass  is  called  acid  humus  (ge'in). 

If  the  decomposition  of  plant-remains  begins  at  first 
with  the  full  access  of  air  and  at  an  ordinary  tempera- 
ture, but  is  afterwards  continued  under  water  without 
the  access  of  air,  the  humus  substance  richest  in  carbon, 
which  is  known  as  peat,  is  formed. 

Between  these  different  products  of  decomposition  are 
found  gradual  transitions  into  each  other,  so  that  the 
humus  substances  represent  no  fixed  chemical  combina- 


DETERMINATION   OF   THE   SOIL-CONSTITUENTS.       73 

tions.  For  agriculture,  it  is  first  of  all  of  importance 
to  know  the  distribution  of  the  humus  substance  in  the 
soil  and  its  reaction.  The  distribution  and  the  degree  of 
decomposition  are  learned  from  mechanical  analysis  by  a 
microscopic  examination  of  the  various  products  of 
elutriation.  The  reaction  is  best  learned  by  laying  a 
moist  sample  of  soil  upon  blue  litmus-paper  and  observ- 
ing whether  the  test  paper  is  more  or  less  strongly 
reddened.  Since,  however,  the  free  carbonic  acid  present 
in  the  soil  may  also  redden  the  paper,  in  making  the 
experiment,  the  latter  has  to  be  dried  and  examined  as 
to  whether  the  reddening  remains  visible  after  drying. 
Sour  humus  soils  are  very  detrimental  to  cultivation. 

In  regard  to  the  quantitative  determination  of  the 
humus  substances,  their  content  of  carbon  can,  with  ap- 
proximate accuracy,  be  determined  by  Knop's  method. 
If,  however,  it  is  to  be  determined  with  the  greatest 
accuracy  possible,  combustion,  customary  in  elementary 
analysis,  has  to  be  employed.  With  some  soils  a  guide 
for  judging  the  content  of  humus  is  already  obtained  by 
determining  the  loss  in  igniting. 

a.  Knop's  method  for  the  determination  of  humus. — 
Knop's  method  is  based  upon  the  conversion  of  the  car- 
bon contained  in  the  humus  by  oxidation  with  chromic 
acid  into  carbonic  acid,  and  collecting  the  latter  in  a 
weighable  absorption-apparatus. 

Spread  about  t\vo  to  ten  grammes  of  fine  soil  (less 
than  two  millimeters  in  diameter)  of  the  substance  to  be 
examined  upon  a  watch  crystal  and  dry  it  for  at  least 
one  hour  at  212°  F.  in  a  drying  chamber.  The  drying 
chamber  shown  at  Fig.  1 2  has  been  devised  by  Dr.  R. 
Muencke,  of  Berlin,  and  can  be  highly  recommended 


74  THE   EXAMINATION    OF   SOILS. 

for  drying  at  a  constant  temperature.  The  box  of 
strong  sheet-iron  is  provided  with  double  walls,  so  that 
the  hot  gases  of  combustion  in  the  interspace  between 

Fig.  12. 


the  walls  surround  the  entire  box  on  all  sides,  with  the 
exception  of  the  door,  which  is  also  double- walled. 
The  outside  of  the  box  is  surrounded  with  a  jacket  of 
asbestos  card-board.  The  gases  of  combustion  escape 


DETERMINATION   OF   THE   SOIL-CONSTITUENTS.      75 

through  apertures  in  the  top  of  the  box,  which  can  be 
more  or  less  opened  by  a  slide.  The  two  tubes  serve 
for  the  reception  of  a  thermometer  and  a  heat  regu- 
lator. A  glass  plate  provided  with  two  holes  is  placed 
in  the  interior  immediately  under  the  top  of  the  box. 
The  heating  which  is  very  uniform  is  effected  by  means 
of  a  gas-spiral  with  twenty  small  flames,  which  can  be 
regulated  by  two  screws. 

The  temperature  of  212°  F.  should  never  be  ex- 
ceeded since,  already,  at  230°  F.,  the  water  distilling  from 
the  humus  sometimes  shows  a  brownish  color  which 
indicates  decomposition.  Together  with  the  substance  a 
weighing-flask  is  placed  in  the  drying-chamber,  the  air- 
tight ground-in  stopper  of  the  flask  being  however  first 
removed.  When  the  substance  is  dry,  it  is  brought  hot 
into  the  weighing-flask,  and,  after  closing  the  latter  with 
the  stopper,  it  is  allowed  to  cool  in  the  desiccator.  It  is 
then  weighed,  and  one  to  ten  grammes  of  the  substance, 
according  to  its  greater  or  smaller  content  of  humus,  are 
carefully,  without  scattering  any  dust,  brought  into  a 
small  glass  flask  with  a  wide  neck,  in  which  oxidation 
of  the  humus  substance  is  to  be  carried  on.  For  this 
purpose  the  apparatus  for  the  determination  of  carbonic 
acid,  Fig.  8,  may  be  used.  If,  however,  such  an  appa- 
ratus is  not  at  hand,  place  in  the  glass  flask  a  doubly 
perforated  rubber  cork.  Through  one  of  the  perfora- 
tions passes  a  glass  tube  somewhat  bent  on  the  bottom 
and  closed  above  with  a  small  piece  of  a  glass  rod  in 
rubber  tubing.  Through  the  other  perforation  passes 
the  calcium  chloride  tube  which  is  bent  above  the  cork 
and  otherwise  has  the  same  shape  as  described  under 
Fig.  8.  In  the  beginning  of  the  operation  it  is  best  not 


76  THE   EXAMINATION   OF   SOILS. 

to  dip  the  straight  tube  into  the  fluid,  as  otherwise  it  may 
easily  clog  up  below  by  the  separated  chromic  acid. 

Pour  over  the  weighed  substance  in  the  flask  20  to  30 
cubic  centimeters  of  distilled  water,  and  add  30  to  40 
cubic  centimeters  of  concentrated  sulphuric  acid,  which 
is  best  gradually  introduced  through  a  funnel.  On  the 
acid  mixing  with  the  water  strong  heating  takes  place, 
so  that  the  free  carbonic  acid  present  in  the  soil,  as  well 
as  that  fixed  on  lime,  is  completely  expelled.  If  much 
calcium  carbonate  is  present,  as  is,  for  instance,  the  case 
with  moor-marls,  the  sulphuric  acid  must  be  very  gradu- 
ally introduced,  with  frequent  cooling  of  the  vessel,  as 
otherwise  the  fluid  might  foam  over.  Before  commence- 
ment of  oxidation  the  flask  is  allowed  to  completely  cool 
off  and  the  air  over  the  fluid  sucked  off  to  remove  the 
last  traces  of  carbonic  acid. 

Since  plant-remains  not  entirely  converted  into  humus 
frequently  occur  in  soils,  and  cannot  be  well  sorted 
out,  the  substance  is  allowed  to  remain  in  contact 
with  the  sulphuric  acid  for  some  days.  Carbonization 
of  the  organic  remains  now  takes  place,  and  oxidation 
with  chromic  acid  is  effected  more  rapidly  and  uni- 
formly. 

After  connecting  the  previously  weighed  Geissler  ab- 
sorption-apparatus (Fig.  9),  with  the  calcium  chloride 
tube,  10  to  15  grammes  of  pulverized  potassium  bichro- 
mate are  quickly  poured  upon  the  substance  through  a 
paper  tube  inserted  in  the  flask,  and  the  apparatus  is 
immediately  closed.  To  avoid  errors,  which  might 
originate  from  the  fluid  spurting  against  the  rubber  cork 
in  case  of  a  very  violent  evolution  of  carbonic  acid,  it  is 
best  to  cover  the  lower  side  of  the  cork  with  thin 


DETERMINATION   OF   THE   SOIL-CONSTITUENTS.      77 

platinum  sheet.  A  very  small  flame  is  now  brought 
under  the  flask  and  the  evolution  of  carbonic  acid 
beginning  with  the  heating  is  so  regulated  that  one 
bubble  per  second  passes  through  the  Geissler  apparatus. 
If  evolution  becomes  more  vigorous,  moderate  the 
flame,  and  if  it  abates,  heat  more  strongly. 

By  the  sulphuric  acid,  the  potassium  bichromate  is 
decomposed  as  follows:  O2O7K2  +  H2SO4  =  2(CrO3)  + 
K2SO4  +  H2O.  By  its  oxygen  the  free  chromic  acid 
oxidizes  the  carbon  of  the  humus  substances  to  carbonic 
acid.  An  excess  of  sulphuric  acid  being  always  present, 
chrome-alum  (SO4)2CrK  4-  12H2O)  is  generally  formed 
in  the  fluid.  The  heating  is  increased  to  boiling  until  a 
perceptible  evolution  of  carbonic  acid  no  longer  takes 
place.  Finally,  the  straight  glass  tube  is  dipped  in  the 
fluid  and  connected  with  a  potash  wash  bottle,  while  a 
slow  current  of  air  is  sucked  through  the  entire  appa- 
ratus. The  flame  is  now  removed,  and,  for  the  rest,  the 
operation  carried  on  as  given  under  "  determination  of 
carbonic  acid  by  direct  weighing." 

To  approximately  calculate  from  the  carbonic  acid 
found,  the  quantity  of  humus  free  from  water  and 
nitrogen,  it  has  been  agreed  to  take  58  per  cent,  as  the 
average  content  of  carbon  in  the  humus  no  matter  in 
which  form  it  may  occur  in  the  soil.  Hence,  in  order 
to  find  the  content  of  humus,  the  quantity  of  carbonic 
acid  found  need  only  be  multiplied  by  the  factor  0.471. 

Since  errors  may  originate  in  the  presence  of  ferrous 
sulphide  by  the  development  of  small  quantities  of  sul- 
phuretted hydrogen,  or  in  the  presence  of  chlorides,  by 
escaping  hydrochloric  acid  gas,  it  is  recommended  to 
insert  between  the  calcium  chloride  tube  and  the  Geissler 


78  THE   EXAMINATION   OF   SOILS. 


apparatus  a  U-tube-  The  latter  is  filled  with  pieces  of 
pumice  previously  saturated  with  blue  vitriol  and  heated 
until  the  latter  is  dehydrated.  By  this  means  the  sul- 
phuretted hydrogen  and  hydrochloric  acid  gas  are  re- 
tained. 

6.  Determination  of  the  carbon  of  the  humus  substances 
by  elementary  analysis.  —  The  object  of  the  method  to  be 
discussed  here,  which  was  first  mentioned  by  Liebig,  is  to 
burn  the  carbon  to  carbonic  acid  by  igniting  together 
with  cupric  oxide.  Since,  however,  the  humus  substances 
of  the  soil  always  contain  nitrogen  which,  by  this  mode 
of  combustion,  is  converted  partially  into  nitrous  gas  and 
nitrous  acid,  the  method  is  accordingly  modified. 

To  effect  this  analysis  by  combustion,  a  hard  Bohemian 
glass  tube  from  50  to  55  centimeters  long  is  used.  After 
being  thoroughly  cleansed,  one  end  is  drawn  out  and 
turned  over  in  the  shape  of  a  beak,  while  the  other  end 
is  fused  together.  The  tube  is  heated  upon  the  sand 
bath,  and,  after  removing  the  air  contained  in  it  by 
sucking  with  a  glass  tube,  it  is  filled  half  full  with  pure, 
freshly  ignited  and  still  warm  cupric  oxide,  introduced 
through  a  previously  heated  metallic  funnel,  care  being 
had  that  none  of  the  cupric  oxide  reaches  the  beak- 
shaped  portion.  This  is  best  prevented  by  loosely 
inserting,  before  filling,  a  cork  of  pure  asbestos.  Now 
pour  some  warm  cupric  oxide  into  a  heated  porcelain 
mortar  and  add  0.5  to  10  grammes  of  the  finely  pulve- 
rized fine  soil,  the  quantity  depending  on  the  larger  or 
smaller  content  of  humus.  The  cupric  oxide  is 
intimately  combined  with  the  fine  soil  and  the  mixture 
also  brought  into  the  tube.  Any  particles  adhering  to 
the  mortar  are  removed  by  rubbing  them  together  with 


DETERMINATION   OF   THE   SOIL-CONSTITUENTS.      79 

some  fresh  cupric  oxide  and  adding  this  mixture  to  the 
other  in  the  tube.  Suppose  the  whole  occupies  a  space 
of  5  centimeters  in  the  tube.  Then  add  5  centimeters 
more  of  cupric  oxide ;  upon  this  follows  a  layer  of  10 
to  12  bright,  fine  copper  wire  shavings  or  a  copper  wire 
spiral  of  the  same  length.  It  is  still  better  to  use 
spirals  of  very  fine  silver  wire,  which,  besides  completely 
reducing  the  nitrous  gas,  also  retain  any  chlorine  present 
by  the  formation  of  silver  chloride.  The  tube  having 
been  filled,  rap  repeatedly  with  it  lengthwise  upon  a 
table  so  that  a  channel  is  formed  on  top  of  the  contents 
through  which  the  gases  of  combustion  can  escape.  The 
tube  thus  filled  is  provided  with  a  calcium  chloride  tube 
which  is  joined  by  a  forked  glass  tube.  One  end  of  this 
tube  is  connected  with  a  water  air-pump  and  the  other 
provided  with  rubber  tubing  and  a  clip.  While  the 
combustion  tube  is  being  pumped  out,  dried  air  is  allowed 
to  enter  by  means  of  the  clip  through  the  calcium 
chloride  tube,  so  that  all  moisture  is  thereby  removed. 

The  tube  thus  prepared  is  placed  in  a  combustion 
furnace  (Fig.  13),  the  empty  space,  about  five  centimeters 
long,  being  allowed  to  project  from  the  furnace,  while 
the  perforated  rubber  cork  closing  the  tube  is  protected 
by  a  piece  of  asbestos  card-board.  The  tube  is  connected 
to  a  previously  weighed  calcium  chloride  tube  and  the 
latter  to  the  weighed  Geissler  potash-apparatus  also, 
provided  with  a  calcium  chloride  tube. 

Combustion  should  be  conducted  as  slowly  as  possible. 
After  the  whole  arrangement  has  been  found  perfectly 
air-tight,  the  front  and  back  parts  of  the  tube  are  heated, 
and,  when  red-hot,  the  portion  of  the  tube  containing 
the  substance  is  gradually  heated,  the  heat  being  so 


80 


THE   EXAMINATION   OF   SOILS. 


regulated  that  one  bubble  per  second  passes  through  the 
potash-apparatus. 

The  operation  is  finished  as  soon  as  with  strong  heat- 
ing the  potash  solution  begins  to  pass  back  into  the  bulb 
nearest  to  the  apparatus.  The  extreme  point  of  the  tube 

Fig.  13. 


is  then  Broken  off  and  the  main  gas-cock  closed.  The 
bent-up  portion  of  the  tube  must  not  be  too  strongly  heated 
so  that  it  can  be  connected  by  means  of  a  rubber  tube 
with  a  potash  wash-bottle.  A  calcium  chloride  tube  is 
inserted  between  the  combustion  tube  and  the  potash 
wash-bottle,  so  that  no  moisture  from  the  potash  solution 
can  reach  the  front  calcium  chloride  tube.  After  con- 
necting the  calcium  chloride  tube  of  the  Geissler  potash- 
apparatus  with  the  aspirator  described  under  "determina- 
tion of  carbonic  acid/'  a  slow  current  of  air  is  allowed 


DETERMINATION   OF   THE  SOIL-CONSTITUENTS.      81 

to  pass  through  the  combustion  tube  in  order  to  expel 
all  the  carbonic  acid  from  it. 

After  finishing  the  operation,  the  Geissler  potash 
apparatus  and  the  (J-tube  of  the  calcium  chloride  tube 
are  brought  into  the  weighing-room  and  allowed  to  stand 
for  half  an  hour  to  acquire  the  temperature  of  the  room 
before  weighing  them  separately.  The  water  weighed 
in  the  U-tube  contains  the  entire  hydrogen,  that  of  the 
humus  substances  as  well  as  that  fixed  to  the  other  soil 
constituents. 

To  calculate,  from  the  quantity  of  carbonic  acid  ab- 
sorbed by  the  Geissler  potash  apparatus,  the  content  of 
carbon  in  the  soil,  multiply  it  with  the  factor  0.273. 
If,  however,  the  humus  substance  is  to  be  determined, 
multiply  the  weighed  carbonic  acid  by  the  factor  0.471. 

c.  Determination  of  the  loss  by  ignition. — If  the  sample 
of  soil  to  be  examined  contains  no  clay,  or  only  a  very 
small  quantity  of  it,  the  humus  can  be  approximately 
ascertained  by  determining  the  loss  by  ignition. 

The  fine  soil  dried  continuously  at  212°  F.  is  poured 
into  a  previously  weighed  porcelain  crucible,  and  the 
latter  again  weighed.  Now  heat  the  crucible  very 
gradually  by  placing  it  obliquely  upon  a  triangle  and 
advancing  it  from  the  outer  edge  towards  the  small  flame 
of  a  Bunseii  burner.  Then  heat  gradually  after  placing 
the  lid  upon  the  crucible,  and  regulate  the  combustion 
of  the  substance  so  that  no  small  particles  can  be  carried 
away  by  the  draught.  When  combustion  of  the  humus 
is  complete,  accelerate  entire  incineration  by  stirring 
with  a  stout  platinum  wire,  the  lower  end  of  which  has, 
by  hammering  upon  an  anvil,  been  given  the  shape  of  a 
spatula. 


82  THE   EXAMINATION   OF  SOILS. 

For  the  determination  of  loss  by  ignition  Knop  uses 
two  grammes  of  fine  earth,  mixes  the  residue  from 
ignition  with  pure  pulverulent  oxalic  acid  and  gradually 
raises  the  temperature  until  the  oxalic  acid  just  begins  to 
decompose.  This  operation  is  repeated  with  one-half 
the  quantity  of  oxalic  acid  until  the  crucible,  after  cool- 
ing and  weighing,  shows  a  constant  weight.  The 
crucible  must  not  be  too  strongly  heated,  as  otherwise  a 
portion  of  the  carbonic  acid  regenerated  by  the  oxalic 
acid  is  again  expelled. 

According  to  another  method,  the  residue  from 
ignition  is  repeatedly  moistened  with  ammonium  carbon- 
ate and  slightly  ignited  to  regenerate  .the  alkaline  earths 
present  in  small  quantity,  then  dried  at  302°  F.,  and, 
after  cooling  in  the  desiccator,  weighed. 

If,  however,  larger  quantities  of  the  carbonates  of 
calcium  and  magnesium  are  present,  and  heating  has 
been  carried  on  to  a  higher  degree  in  order  to  destroy 
all  organic  substances,  the  oxides  of  calcium  and  mag- 
nesium cannot  be  regenerated,  since,  by  the  intimate 
mixture  of  the  alkaline  earths  with  dust-like  silica, 
silicates  are  formed  which  cannot  be  reconverted  into 
carbonates.  In  such  a  case,  it  is  advisable  to  carefully 
bring  the  residue  from  ignition  into  a  platinum  crucible 
and  heat  the  latter  until  all  the  carbonic  acid  is  expelled 
and  fusible  calcium  silicate  has  been  formed.  The  car- 
bonic acid  of  the  initial  substance  is  determined  in  a 
special  sample  and  deducted  from  the  loss  by  ignition. 
The  vesicular  slag  is  best  removed  from  the  platinum 
crucible  by  dissolving  it  in  fluoric  acid. 

C.  Determination  of  the  content  of  clay. — Formerly 
the  content  of  clay  was  frequently  determined  by  elutriat- 


DETERMINATION   OF   THE   SOIL-CONSTITUENTS.       83 

ing  the  finest  portion  from  the  soil  and  designating  this 
as  clay.  More  accurate  chemical  investigations  have, 
however,  shown  that  a  considerable  quantity  of  quartz- 
flour  is  admixed  with  the  finest  portions,  so  that  the 
content  of  clay  determined  by  elutriation  was  always 
too  high. 

The  object  is  better  attained  by  combining  for  the  de- 
termination of  the  clay,  the  silt-analysis  with  a  chemical 
examination.  It  has  been  shown  that  with  an  elutriat- 
ing velocity  of  0.2  millimeter  the  greater  quantity  of 
clay  contained  in  the  soil  is  elutriated,  and  with  a  velocity 
of  2  millimeters,  the  entire  quantity,  provided  the  sub- 
stance is  previously  thoroughly  loosened  by  boiling. 
Hence,  in  investigating  soils  with  the  intention  of 
simultaneously  determining  the  clay,  elutriation  will 
have  to  be  effected  from  the  beginning  with  distilled 
water  in  order  to  obtain  the  products  of  elutriation  at 
0.2  and  2.0  millimeters  per  second  as  pure  as  possible. 
If  the  clay  alone  is  to  be  determined,  it  is  best  to  at 
once  elutriate  the  soil  at  2.0  millimeters  velocity.  Soils 
containing  only  small  quantities  of  coarse  material  may 
be  pulverized  in  an  agate  mortar,  and,  without  previous 
elutriation,  be  directly  used  for  the  determination  of  clay. 
If,  however,  in  the  mechanical  analysis,  the  products  of 
elutriation  at  0.2  and  2.0  millimeters'  velocity  have  been 
separated,  they  are,  after  drying  and  weighing,  again 
combined  and  very  carefully  mixed  in  a  dish. 

Disintegration  with  sulphuric  acid  in  a  closed  tube. — 
This  method  of  the  determination  of  clay  is  based  upon 
the  property  of  pure  clay  or  kaolin  dissolving  in  hot 
sulphuric  acid,  while  feldspars  and  quartz  are  not  de- 
composed. In  order  that  the  action  of  the  sulphuric 


84  THE   EXAMINATION   OF  SOILS. 

acid  may  be  as  uuiform  as  possible,  disintegration  is  best 
effected  in  a  closed  glass  tube. 

For  this  purpose  a  hard  Bohemian  glass  tube  about 
30  centimeters  long,  without  the  neck,  is  used.  One  end 
of  the  tube  is  drawn  out  to  a  capillary  which  is  thickened 
by  fusion.  The  other  end  is  also  drawn  out  so  that  a 
neck  is  formed,  which  must,  however,  be  wide  enough 
for  the  convenient  insertion  of  the  weighing-tube. 
Before  use,  the  tube  is  thoroughly  boiled  with  aqua 
regia,  rinsed  with  distilled  water  and  dried. 

For  the  execution  of  the  analysis,  1  or  2  grammes  of 
the  finely  pulverized  substance  are  continuously  dried  at 
212°  F.  and  brought  hot  into  a  long  thin  weighing-tube 
closed  with  a  cork.  After  cooling,  the  substance  is 
poured  into  the  Bohemian  glass  tube  by  pushing  the 
weighing-tube  down  as  far  as  possible  so  as  to  prevent 
any  of  the  substance  from  adhering  to  the  neck.  The 
weighing-tube  is  then  again  weighed. 

By  means  of  a  pipette  20  cubic  centimeters  of  dilute 
sulphuric  acid  (1  volume  of  concentrated  acid  to  5 
volumes  of  water)  are  now  brought  into  the  Bohemian 
glass  tube  and  the  latter  closed  by  drawing  out  the 
neck. 

If  the  substance  contains  carbonate  of  lime,  the  sulphuric 
acid  has  to  be  added  very  gradually,  and  the  tube, 
before  closing  it,  must  be  placed  in  boiling  water,  so 
that  all  the  carbonic  acid  can  escape. 

The  closed  glass  tubes  are  now  placed  in  a  tubular 
furnace  (Fig.  34),  so  arranged  that  it  will  hold  four 
tubes.  They  are  heated  for  six  hours  at  248°  F.,  and 
when  perfectly  cold,  are  opened  by  drawing  a  ring 
around  them  with  a  diamond,  and  holding  the  point  of  a 


DETERMINATION    OF    THE   SOIL-CONSTITUENTS.       85 

red-hot  glass  rod  against  the  mark.  The  glass  breaks 
off  smoothly,  and  the  contents  can  be  conveniently 
emptied  into  a  beaker-glass  with  the  aid  of  a  wash- 
bottle.  The  fluid  is  strongly  diluted,  and,  in  the 


Fi 


presence  of  much  calcium  carbonate,  compounded  with 
some  hydrochloric  acid  to  dissolve  the  gypsum  formed  ; 
it  is  then  covered  with  a  watch  crystal  and  heated  to 
boiling.  After  allowing  the  substance  to  settle,  the 
fluid  is  decanted  off  through  a  filter.  Finally,  the  un- 
dissolved  substance  is  also  brought  upon  the  filter  and 
the  latter  washed  out  with  hot  distilled  water  until  a 
drop  running  off  from  the  funnel  shows  no  perceptible 
turbidity  when  compounded  with  barium  chloride 
solution. 

To  oxidize  the  ferrous  oxide  the  filtrate  is  compounded 


86  THE    EXAMINATION   OF   SOILS. 

with  bromine  water,  and,  after  covering  it  with  a  watch 
crystal,  boiled  until  the  yellow  coloring  disappears  and 
an  odor  of  bromine  is  no  longer  perceptible. 

The  flame  is  now  removed,  and  the  fluid,  being  con- 
stantly stirred  with  a  glass  rod,  is  compounded  with 
dilute  ammonia  until  it  shows  a  slight  ammoniacal  odor, 
and  a  piece  of  red  litmus-paper  thrown  in  acquires  a 
permanent  blue  color.  The  precipitate  formed  consists 
of  aluminium  and  ferric  hydrate  =»  A1(OH)3  4-  Fe- 
(OH)3.  If  too  much  ammonia  has  been  added,  the 
larger  portion  of  it  has  to  be  expelled  by  heating  the 
fluid  for  some  time,  the  aluminium  hydrate  being  some- 
what soluble  in  an  excess  of  ammonia. 

Now,  pour  the  fluid  boiling  hot,  and  without  allowing 
the  precipitate  to  settle,  through  a  filter  so  arranged  that 
filtration  will  be  rapidly  effected.  The  filter  should  only 
be  filled  with  fluid  up  to,  at  the  utmost,  one  centimeter 
from  the  edge,  as  otherwise  the  \vashing  out  of  the  pre- 
cipitate is  very  difficult.  In  filtering,  the  funnel  should 
not  be  allowed  to  become  entirely  empty,  as  otherwise 
the  gelatinous  precipitate  fixes  itself  firmly  to  the  paper, 
clogging  it  up.  After  the  precipitate  has  been  trans- 
ferred from  the  beaker-glass  to  the  filter  and  the  particles 
adhering  to  the  glass  removed  with  a  feather,  the  pre- 
cipitate is  washed  with  hot  water  with  the  aid  of  a  wash- 
bottle,  until  a  drop  running  off  shows  no  turbidity  when 
compounded  with  barium  chloride  solution. 

The  precipitate  of  ferric  oxide  and  aluminia  is  con- 
tinuously dried  in  the  drying-chamber  at  212°  F., 
whereby  it  shrinks  together  so  much  that  it  can  be 
almost  completely  detached  from  the  filter.  Now  lay  a 
sheet  of  white  paper  upon  the  table,  place  upon  it  a 


DETERMINATION   OF   THE   SOIL-CONSTITUENTS.      87 

weighed  platinum  crucible  and  bring  the  precipitate  into 
the  latter  by  rubbing  the  interior  sides  of  the  paper 
against  each  other.  Any  scattering  grains  fall  upon  the 
paper  and  are  also  brought  into  the  crucible.  The  pre- 
cipitate being  detached  as  much  as  possible  from  the 
filter,  the  latter  is  folded  together,  wrapped  round  with 
thin  platinum  wire  and  burnt  in  the  point  of  the  flame 
of  a  Buusen  burner.  When  the  coal  of  the  filter  is 
completely  burnt,  add  the  ash  to  the  precipitate  in  the 
crucible  and  strongly  ignite  the  latter  for  some  time, 
commencing  however  with  a  moderate  heat,  the  crucible 
being  covered  with  the  lid.  Then  allow  the  crucible 
and  its  contents  to  cool  in  the  desiccator,  and  weigh  as 
rapidly  as  possible,  since  both  the  ferric  oxide  and 
aluminia  are  quite  hygroscopic.  After  deducting  the 
filter-ash,  the  quantity  of  ferric  oxide  and  alumina  = 
A12O3  -f-  Fe2O3  dissolved  by  sulphuric  acid  is  found. 

Separation  of  the  ferric  oxide  from  the  alumina,  a. 
Determination  of  the  iron  as  ferrous  oxide  by  titration 
with  potassium  permanganate  solution. — The  ignited  and 
weighed  precipitate  of  ferric  oxide  and  alumina  is  care- 
fully, without  scattering  anything,  poured  from  the 
platinum  crucible  into  a  small  glass  flask  with  a  long 
neck.  The  particles  adhering  to  the  crucible  are  de- 
tached with  a  feather  and  washed  by  means  of  a  wash- 
bottle  into  the  flask.  Add  to  the  water  about  an  equal 
volume  of  pure  hydrochloric  acid  and  place  the  flask 
obliquely  inclined  upon  the  sand  bath,  which  is  suf- 
ficiently heated  to  bring  the  fluid  to  boiling.  The 
oblique  inclination  of  the  neck  of  the  flask  is  necessary 
to  avoid  loss  by  squirting  in  consequence  of  the  bump- 
ing of  the  fluid  during  boiling.  If,  inside  of  a  few 


88  THE   EXAMINATION   OF   SOILS. 

hours,  the  precipitate  is  not  entirely  dissolved,  add  to  the 
strongly  evaporated  fluid  a  mixture  of  hydrochloric  acid 
and  water,  and  heat  again  until  the  entire  precipitate  is 
dissolved.  If  a  few  white  flakes  should  remain,  they 
consist  mostly  of  silica  or  titanic  acid ;  the  quantity  is, 
however,  generally  so  small  that  no  notice  need  be  taken 
of  them.  When  the  solution  in  the  flask  is  cold,  com- 
pound it  with  dilute  sulphuric  acid,  again  place  the  flask 
in  an  oblique  position  on  the  sand-bath  and  heat,  in 
order  to  expel  the  hydrochloric  acid,  and  convert  the 
chlorides  of  iron  and  alumina  into  sulphates,  until  the 
fluid  is  quite  evaporated  and  clear  as  water.  Dilute  the 
cold  solution  with  water,  and  compound  it  again  with 
pure  dilute  sulphuric  acid. 

In  order  to  dissolve  the  iron  in  the  ignited  precipitate 
of  iron  and  alumina,  another  method  may  be  used, 
which,  however,  has  the  disadvantage  that  the  substance 
has  to  be  previously  powdered  in  an  agate  mortar, 
whereby  slight  particles  may  readily  be  lost,  again 
ignited  in  the  platinum  crucible  and  weighed.  The 
powder  is  then  compounded  with  ten  times  its  quantity 
of  previously  fused  potassium  bisulphate  and  heated  in 
the  covered  platinum  crucible  until  the  powder  is  com- 
pletely dissolved.  After  cooling,  the  melt  is  dissolved 
with  hot  water  and  compounded  in  a  boiling  flask  with 
pure  dilute  sulphuric  acid. 

Now  add  to  the  iron  solution,  obtained  by  either  one 
of  the  two  methods,  pure  granulated  zinc,  and  place  a 
small  funnel  upon  the  boiling  flask.  Should  the  evolu- 
tion of  hydrogen,  which  now  takes  place,  be  not  suf- 
ficiently vigorous,  it  may  be  promoted  by  dipping  the 
point  of  a  glass  rod  in  platinum  chloride  and  after 


DETERMINATION   OF  THE  SOIL-CONSTITUENTS.      89 

allowing  the  drop  adhering  to  it  to  drop  off,  injecting 
what  remains  on  the  rod  into  the  flask  by  means  of  the 
wash-bottle.  A  vigorous  evolution  of  hydrogen  will  at 
once  commence.  Hydrogen  in  a  nascent  state  possesses^ 
as  is  well  known,  the  property  of  converting  ferric 
oxides  into  ferrous  oxides,  or,  according  to  the  more 
modern  conception,  of  transforming  the  trivalent  into 
bivalent  iron. 

The  reduction  of  the  solution  may  also  be  promoted 
by  placing  the  flask  on  a  moderately  heated  sand-bath. 
AVhen  evolution  of  hydrogen  has  vigorously  continued 
for  about  one  hour,  the  solution  is  tested  as  to  the  com- 
plete reduction  of  the  iron.  This  is  effected  by  taking, 
by  means  of  a  glass  rod,  a  drop  of  the  fluid  from  the 
flask  and  allowing  it  to  run  upon  a  white  porcelain  plate 
into  a  drop  of  freshly  prepared,  not  too  concentrated 
potassium  sulphocyanate  solution.  If  the  latter  is 
reddened,  reduction  is  not  finished  and  has  to  be  con- 
tinued, with  the  addition  of  some  zinc  and  sulphuric 
acid  if  necessary,  until  a  repeated  test  shows  no  colora- 
tion of  the  potassium  sulphocyanate  solution.  When 
the  solution  is  completely  reduced,  pour  it  rapidly 
through  a  funnel  in  which  a  glass-wool  cork  has  been 
loosely  inserted.  In  doing  this,  a  current  of  pure  car- 
bonic acid  should  be  conducted  above  upon  the  funnel, 
as  well  as  into  the  beaker-glass  beneath  it,  so  that  during 
filtering  no  oxidation  of  the  solution  by  the  oxygen  of 
the  air  can  take  place.  The  flask,  together  with  the 
zinc  remaining  therein,  is  rinsed  with  distilled  water, 
and  the  rinsing  water  also  poured  through  the  funnel. 
The  filtrate,  which  should  not  be  hot,  is  further  com- 
pounded with  some  dilute  sulphuric  acid,  and  the 


90  THE   EXAMINATION   OF   SOILS. 

solution  is  then  titrated  with  previously  standardized 
potassium  permanganate  solution. 

Standardizing  of  the  potassium  permanganate  solution. 
— The  potassium  permanganate  solution  is  prepared  and 
standardized  as  follows  : — 

Dissolve,  with  the  assistance  of  heat,  1  gramme  of 
pure  crystallized  potassium  permanganate  in  distilled 
water,  and  add  to  the  solution  sufficient  water  to  make 
1  liter.  The  solution  thus  prepared  will  keep  for  some 
time  in  a  glass-stoppered  bottle,  but  should  not  be  ex- 
posed to  the  direct  light  of  the  sun. 

The  solution  is  standardized  by  measuring  in  a  burette 
with  a  glass  stop-cock  as  many  cubic  centimeters  of  it 
as  are  required  for  just  imparting  to  a  ferrous  oxide 
solution  of  known  content  a  violet  color.  For  prepar- 
ing this  iron  solution  iron-ammonium  alum  or  ammonio- 
ferric  sulphate  is  used.  This  salt,  being  seldom  found 
pure  in  commerce,  is  purified  by  dissolving  a  quantity  of 
it  in  hot  distilled  water  to  which  a  few  drops  of  sulphuric 
acid  have  been  added,  until  a  film  of  salt  commences  to 
separate.  The  beaker-glass  containing  the  concentrated 
solution  is  then  placed  in  cold  water  and  the  solution 
constantly  stirred  with  a  glass  rod,  so  that  the  salt  sepa- 
rates as  a  fine  crystalline  powder.  When  the  fluid  is 
perfectly  cold,  it  is  separated  from  the  salt  by  pouring 
it  into  a  funnel  provided  with  a  platinum  cone,  which, 
by  means  of  a  doubly  perforated  rubber  cork,  is  placed 
upon  a  glass  flask.  Through  the  other  perforation  of 
the  cork  passes  a  glass  tube  which  is  connected  with  a 
water  air-pump.  When  nothing  more  drips  off,  the 
glass  flask  is  exchanged  for  another,  and  the  precipitate 
rinsed  with  a  mixture  of  two  parts  absolute  alcohol  and 


DETERMINATION   OF   THE  SOIL-CONSTITUENTS.      91 

one  part  distilled  water.  The  salt  is  pressed  between 
blotting-paper  until  perfectly  dry.  A  solution  of  it 
must  be  reddened  by  potassium  sulphocyanate. 

Of  the  perfectly  dry  ammonio-ferric  sulphate,  accu- 
rately weigh  out  two  portions  of  0.1  gramme  each,  and 
pour  them  into  two  beakers.  Shortly  before  use,  dis- 
solve the  salt  in  200  cubic  centimeters  of  water  to  which 
some  dilute  sulphuric  acid  has  been  added.  The  burette 
provided  with  a  glass  stop-cock  should  have  a  capacity 
of  at  least  30  cubic  centimeters,  and  be  graduated  into 
tenths  of  a  cubic  centimeter.  It  is  filled  to  the  0  point 
with  potassium  permanganate  solution,  and  for  more 
convenient  reading  a  small  float  is  put  in  it.  The  foot 
of  the  burette  stand  is  best  covered  with  a  dead  white 
glass  plate,  or,  if  such  an  arrangement  cannot  be  had,  a 
piece  of  white  paper  is  placed  under  the  beaker  contain- 
ing the  ammonio-ferric  sulphate  solution.  Now  allow 
the  potassium  permanganate  solution  to  flow  slowly  from 
the  burette  into  the  ammonio-ferric  sulphate  solution, 
stirring  constantly  with  a  glass  rod.  The  red  color  of 
the  potassium  permanganate  solution  at  first  disappears 
very  rapidly,  but  later  on  more  slowly,  so  that  in  order 
to  hit  the  exact  point,  the  solution  must  finally  be 
admitted  only  drop  by  drop.  When  finally  all  the  iron 
is  oxidized,  one  drop  suffices  to  very  slightly  color  the 
fluid.  The  operation  is  finished  when  this  coloration 
lasts  a  few  minutes  after  stirring.  Now,  after  waiting  a 
short  time  to  allow  the  fluid  from  the  walls  of  the 
burette  to  run  together,  read  off  the  number  of  cubic 
centimeters  of  potassium  permanganate  solution  used. 
To  control  the  correctness  of  the  first  reading,  the 


92  THE   EXAMINATION   OF  SOILS. 

experiment  is  repeated  with  the  other  quantity  of  salt 
weighed  out. 

Since  the  quantity  of  iron  contained  in  the  ammonio- 
ferric  sulphate  amounts  to  \,  or,  to  be  more  exact,  to 
T-"ocfiir>  ^  'IS  necessary,  in  order  to  find  the  iron  in  the 
quantity  weighed  off,  to  divide  the  latter  by  7,  or,  what 
is  the  same,  to  multiply  it  by  the  factor  0.143.  To  cal- 
culate the  quantity  of  ferrous  oxide  equivalent  to  the 
quantity  of  salt  weighed  out  multiply  by  the  factor 
0.184,  and  to  find  the  ferric  oxide  with  the  factor  0.204. 
With  the  assistance  of  the  figure  found,  the  effective 
value  of  the  potassium  permanganate  solution  is  calcu- 
lated according  to  the  following  proposition  : — 

Ccm.  of  potassium  permanganate  solution  consumed : 

rFe 

g-l  FeO  =  100  ccm  :  xg. 
iFeA 

The  titration  of  the  ferric  oxide  solution  reduced  by 
hydrogen  is  effected  in  exactly  the  same  manner  as  the 
standardizing  of  the  potassium  permanganate  solution 
just  described.  However,  to  obtain  a  sharp  final  re- 
action, the  potassium  permanganate  solution  must, 
towards  the  last,  be  very  carefully  added  drop  by  drop. 
From  the  quantity  of  potassium  permanganate  solution 
consumed,  the  equivalent  quantity  of  ferric  oxide  is  then 
calculated.  The  percentage  of  ferric  oxide  deducted 
from  the  total  percentage  of  ferric  oxide  and  alumina 
gives  the  percentage  of  alumina  by  difference. 

b.  Calculation  of  the  content  of  clay  in  the  total  soil. — 
To  find  the  content  of  clay  in  the  soil,  calculate  for  the 
quantity  of  alumina  found  the  equivalent  quantity  of 
clay  containing  water,  according  to  Forchhammer's 


DETERMINATION    OF   THE   SOIL-CONSTITUENTS.      93 

formula  (Al2O32[SiOJ  +  2H2O),  by  multiplying  the 
weighed  quantity  of  alumina  by  the  factor  2.5294. 
Since  the  quantity  of  clay  in  the  argilliferous  particles 
(less  than  0.05  millimeters  in  diameter)  has  been  deter- 
mined, the  percentage  of  clay  in  the  total  soil  is  calcu- 
lated. 

With  very  fine  soils,  especially  loess  and  fat  clammy 
soils,  as  well  as  such  as,  on  account  of  their  strongly 
humus  nature,  cannot  be  subjected  to  silt  analysis,  the 
disintegration  with  sulphuric  acid  in  the  tube  will  have 
to  be  at  once  executed  with  the  total  soil.  With  humus 
soils  it  will,  however,  be  better  to  retain  the  method 
of  disintegration  with  concentrated  sulphuric  acid  by 
heating  in  an  open  platinum  dish.  It  was  formerly 
almost  generally  used  for  the  determination  of  clay, 
though  it  does  not  yield  as  uniform  results  as  disintegra- 
tion in  the  tube  in  which  the  concentration  of  the  sul- 
phuric acid,  its  quantity,  the  temperature  and  time  of 
action  can  be  uniformly  regulated. 

Fesca  and  others  have  frequently  drawn  attention  to 
the  fact  that  a  portion  of  the  alumina  contained  in  the 
soil  is  soluble  in  hydrochloric  acid,  and  is  not  referable 
to  clay  according  to  Forchhammer's  formula.  Fesca 
believes  that  this  quantity  of  alumina  soluble  in  hydro- 
chloric acid  indicates  zeolitic  silicates.  Though  the 
correctness  of  this  opinion  is  by  no  means  proved,  in 
very  accurate  and  comprehensive  soil  investigations,  it 
will  be  of  interest  to  treat  the  argilliferous  portions  (less 
than  0.05  millimeter  in  diameter),  with  hot  concen- 
trated hydrochloric  acid  and  to  disintegrate  the  residue 
remaining  thereby  with  sulphuric  acid  in  the  tube. 

However,  for  the  approximate  quantitative  determiua- 


94  THE   EXAMINATION   OF   SOILS. 

tion  of  clay  as  a  soil  constituent,  it  is  better  to  calculate 
the  total  alumina  in  dust  and  finest  disintegrable 
particles  as  clay  for  the  entire  soil.  Most  soils  do  not 
contain  the  clay  in  a  pure  form,  as  already  shown  by 
Forch  hammer's  clay  formula,  but  it  is  rather  a  collective 
term  for  all  silicates  more  or  less  in  a  state  of  decom- 
position or  already  decomposed.  For  agricultural 
purposes,  it  is  of  importance  to  be  able  to  express  the 
content  of  clay,  as  well  as  that  of  humus,  in  fixed 
numerical  values,  and  it  does  not  much  matter  whether 
in  each  separate  case  an  exact  petrographic  equivalent  is 
thereby  designated,  especially  not,  when  still  further  ex- 
periments regarding  the  physical  properties  of  the  soil 
are  to  be  made. 

D.  Determination  of  the  content  of  sand. — According 
to  its  chemical  composition,  the  soil-constituent,  sand, 
may  represent  something  of  very  dissimilar  nature.  Sand 
being  a  transported  product  of  the  disintegration  and 
elutriation  of  heterogeneous  minerals  and  rocks,  it  showrs 
many  variations  in  its  perfected  state.  However,  the. 
minerals  disintegrating  with  the  greatest  difficulty, 
especially  quartz,  will  always  preponderate  in  it.  If  the 
mechanical  analysis  is  carefully  executed,  and  with 
grains  more  than  0.05  millimeter  in  diameter,  the  sand 
can,  with  an  elutriating  velocity  of  2.0  millimeters  per 
second,  be  quite  completely  separated  from  the  clayey 
particles,  and,  hence,  by  the  mechanical  analysis  already 
described,  the  content  of  sand  and  its  granulation  are 
found. 

Petrographic  determination  of  the  coarser  admixed 
parts  of  the  sand. — The  petrographic  determination  of 
the  coarser  admixed  parts  of  the  sand  is  geologically  of 


DETERMINATION   OF   THE   SOIL-CONSTITUENTS.      95 

importance,  since  it  discloses  the  origin  and  formation 
of  the  soil.  In  an  agricultural  respect  it  is  of  value  for 
judging  the  soil,  as,  for  instance,  in  the  presence  of  an 
abundance  of  feldspar,  the  soil  possesses  for  the  future  a 
nearly  inexhaustible  reserve  of  plant-food,  which  be- 
comes only  gradually  available  by  the  progressing  de- 
composition of  the  feldspar. 

A  certain  amount  of  information  regarding  the  nature 
of  these  admixtures  is  obtained  by  sorting  out  and  test- 
ing the  grains  of  sand  of  from  2  to  1  millimeters  in 
diameter,  and  the  gravel  over  2  millimeters  in  diameter. 
For  this  purpose  moisten  the  sample  to  be  examined 
with  water  and  test  the  grains,  best  by  Mohr's  scale  of 
hardness,  as  to  color,  lustre,  and  hardness,  and  further, 
as  to  cleavage,  fusibility,  and  magnetic  properties. 
Small  limestones  are  recognized  by  the  evolution  of 
carbonic  acid  when  treated  with  dilute  hydrochloric 
acid. 

A  further  separation  may  be  effected  by  bringing  the 
admixed  parts  into  specifically  very  heavy  fluids. 

For  this  purpose,  Thoulet  prepares  a  solution  of  2.77 
specific  gravity  (at  from  52°  to  59°  F.)  by  alternately 
introducing  iodide  of  mercury  and  potassium  iodide  in 
water,  and  effects  with  it  the  separation  of  all  bodies  of 
higher  specific  gravity.  By  diluting  the  solution,  bodies 
of  slighter  specific  gravity  may  also  be  separated  from 
each  other. 

Goldschmidt  dissolves  210  grammes  of  potassium 
iodide  and  280  grammes  of  iodide  of  mercury  in  25 
cubic  centimeters  of  distilled  water  and  produces  a 
solution  of  3.196  specific  gravity,  upon  which,  for 
instance,  fluor  spar  (specific  gravity  3.1  to  3.2)  floats. 


96 


THE   EXAMINATION   OF   SOILS. 


Rohrbach  takes  100  parts  of  barium  iodide  and  130 
parts  of  iodide  of  mercury  to  20  cubic  centimeters  of 
water,  heats  in  the  oil  bath  to  from  302°  to  360°  F.,  and 
filters.  The  solution  has  a  specific  gravity  of  3.39,  and 
topaz  floats  upon  it. 

With  the  aid  of  such  solutions  and  the  following 
table  of  specific  gravities,  the  distinct  admixed  parts  of 
the  sand  obtained  by  sifting  or  elutriating  can  be  sepa- 
rated and  determined. 


Gypsum 

2.2    to  2.4 

Augite           .         . 

2.88  to  3.5 

Orthoclase    . 

2.53  "  2.58 

Tourmaline 

2.94       3.24 

Albite  . 

2.62  "  2.67 

Amphibole    . 

2.9         3.3 

Oligoclase 

2.63  "  2.68 

Fluor  spar    . 

3.1         3.2 

Quartz    • 

2.65 

Rutile  . 

4.2         4.3 

Calcareous  spar    . 

2.65  "  2.80 

Heavy  spar  . 

4.3         4.7 

Aiiorthite 

2.67  "  2.76 

Pyrites 

4.9         5.2 

Black  mica  .         . 

2.74  "  3.13 

Magnetic  iron  ore 

4.9         5.2 

Muscovite 

2.76  "  3.1 

E.  Determination  of  the  content  of  quartz. — Since  it  is 
frequently  of  interest  to  determine  the  content  of  quartz 
in  the  sand,  as  well  as  the  dust  and  the  finest  particles, 
J.  Hazard  has  for  this  purpose  proposed  an  indirect 
method,  since  no  process  is  known  for  the  direct  sepa- 
ration of  quartz  in  a  mixture  with  orthoclase,  albite,  and 
oligoclase,  it  being  always  attacked  in  the  disintegration 
of  these  silicates. 

The  finely  pulverized  material  is,  according  to  Hazard, 
fused  with  2  parts  concentrated  sulphuric  and  1  part 
distilled  water,  in  a  hard  Bohemian  glass  tube,  and  for 
six  hours  exposed  to  a  temperature  of  482°  F.  in  a 
tubular  furnace,  whereby  any  muscovite,  biotite,  garnet, 
tourmaline,  talc,  amphibole,  hypersthene,  diallage,  and 
pyroxene  present  is  completely  disintegrated,  while 


DETERMINATION   OF   THE   SOIL-CONSTITUENTS.      97 

orthoclase;  albite,  and  oligoclase  remain  undecom posed. 
The  contents  of  the  glass  tube  are  brought  into  a  dish 
and  the  particles  adhering  to  the  sides  of  the  tube  re- 
moved by  means  of  a  glass  rod  provided  with  a  piece  of 
rubber  tubing.  Before  filtering  off,  the  fluid  is  strongly 
diluted.  The  superficially  washed-out  residue  is  then 
brought  together  with  the  filter  into  moderately  dilute 
potash  lye,  in  order  to  dissolve  the  silica  separated  from 
the  silicates,  and  then  digested  for  one  hour  upon  the 
water  bath.  The  solution  is  diluted  with  water,  filtered 
off  and  the  substance  upon  the  filter  first  washed  with 
hot  dilute  potash  lye,  and  later  on,  with  hot  dilute 
hydrochloric  acid.  The  thoroughly  dried  filter,  together 
with  its  contents,  is  incinerated  in  a  platinum  crucible 
and  weighed. 

The  procedure  is  now  exactly  the  same  as  in  the  sili- 
cate analysis.  The  powder  in  the  platinum  crucible  is 
mixed  with  five  times  its  quantity  of  anhydrous  sodium 
carbonate  and  first  heated  over  an  ordinary  burner,  and, 
later  on,  over  a  blast  lamp,  until  the  mass  flows  quietly 
and  no  more  bubbles  of  carbonic  acid  are  evolved.  The 
hot  crucible  is  placed  upon  a  cold  iron  plate,  whereby, 
in  consequence  of  the  rapid  cooling  off,  the  mass  readily 
becomes  detached  from  the  sides  of  the  crucible.  The 
melt,  as  well  as  the  crucible  itself,  is  brought  into  a 
beaker,  and,  after  pouring  distilled  water  upon  it  and 
covering  the  beaker  with  a  watch-crystal,  the  contents 
are  heated  to  boiling.  Now,  by  means  of  a  pipette,  intro- 
duced through  the  lip  of  the  beaker,  add  in  small  propor- 
tions concentrated  hydrochloric  acid  in  excess,  and  heat 
the  fluid  until  no  more  effervescence  takes  place.  Then 
add  a  few  drops  of  nitric  acid  and  evaporate  the  fluid, 
7 


98  THE   EXAMINATION  OF  SOILS. 

together  with  the  silicate  separated,  in  a  porcelain  dish 
upon  a  water  bath  to  pulverulent  dryness.  As  soon  as 
the  fluid  commences  to  become  thickly-fluid,  it  has  to  be 
constantly  stirred  with  a  glass  pestle,  so  that  no  larger 
cubes  of  common  salt  can  form.  In  order  to  separate 
the  silica  as  a  powder  entirely  insoluble  in  acids,  it  is 
necessary  to  expel  the  hydrochloric  acid  as  completely  as 
possible.  This  is  best  effected  by  adding,  as  soon  as  the 
powder  in  the  dish  becomes  dry,  some  hot  water  and 
again  evaporating,  with  constant  stirring,  to  pulverulent 
dryness.  After  cooling,  moisten  the  powder  with  hydro- 
chloric acid,  pour  hot  water  over  it,  and,  after  several 
times  washing  out  the  silica  in  the  dish  with  hot  water, 
bring  it  upon  the  filter  and  rinse  it  with  hot  water  until  a 
drop  running  off  shows  no  turbidity  when  mixed  with 
nitrate  of  silver.  Before  incinerating  the  filter  with  the 
silica  in  the  platinum  crucible,  it  must  be  completely 
dried  at  212°  F.  It  is  advisable  to  finally  ignite  the 
silica  over  the  blast-lamp,  whereby  it  slags  somewhat 
together  and  is  no  longer  hygroscopic  when  weighed 
after  cooling  in  the  desiccator.  The  filter  ash  is  deducted 
after  weighing. 

In  the  filtrate  from  the  silica,  alumina  and  calcareous 
earth  are  determined  by  successive  precipitation  with 
ammonia  and  ammonium  oxalate  according  to  the 
methods  previously  described  (p.  68  and  p.  86). 

For  the  orthoclase  and  albite,  whose  silica  is  contained 
in  the  total  quantity  of  silica  obtained  from  the  soda 
melt,  Hazard  has  calculated  the  equivalent  quantity  of 
silica  from  the  alumina  found  and  deducted  it  from  the 
total  quantity  of  silica.  The  remainder  represents  the 
quartz  present  in  the  soil.  For  othoclase  and  albite  the 
proportion  of  alumina  to  silicate  is  1  :  3.50878. 


DETERMINATION   OF   THE   SOIL-CONSTITUENTS.      99 

In  the  presence  of  lime  the  alumina  equivalent  to  the 
lime  is  calculated  according  to  Tschermak's  formula  for 
anorthite  in  the  proportion  of  1  calcareous  earth :  1.83214 
alumina,  The  alumina  thus  obtained  is  deducted  from 
the  weighed  total  alumina,  and  the  quantity  of  silica 
required  for  the  albite  and  orthaclase  calculated  to  the 
rest  of  alumina.  For  the  alumina  of  the  anorthite,  the 
quantity  of  silica  belonging  to  it  and  to  be  deducted 
from  the  total  silica  is  calculated  from  the  proportion  1 
alumina:  1.16959  silica. 

E.  Determination  of  the  elementary  composition  of  the 
soil. — If  the  soil  to  be  examined  is  of  homogeneous 
nature,  as,  for  instance,  may  be  the  case  with  pure  clays, 
marly  sands,  or  sands  of  the  subsoil,  it  may  frequently 
be  of  interest  to  learn  the  elementary  composition  of  the 
entire  soil.  For  this  purpose  it  is  advisable  to  simul- 
taneously effect  a  disintegration  with  sodium  carbonate, 
as  well  as  with  fluoric  acid,  the  analytical  results  obtained 
being  best  controlled  in  this  manner. 

a.  Disintegration  with  sodium  carbonate. — For  disinte- 
gration with  sodium  carbonate  pulverize  dust  fine  1  to  2 
grammes  of  the  total  soil  in  an  agate  mortar  and  dry  the 
powder  at  212°  F.  Then  pour  it  from  a  weighing  tube 
into  a  platinum  crucible  and  mix  it  by  means  of  a  plati- 
num spatula  with  5  or  6  times  its  weight  of  anhydrous 
sodium  carbonate.  The  mass  in  the  covered  crucible  is 
heated,  first  over  an  ordinary  burner,  and  finally  fused 
over  the  blast  lamp  until  it  flows  quietly  and  no  more 
carbonic  acid  escapes.  The  glowing  crucible  is  placed 
upon  a  cold  iron  plate  whereby  the  melt  quickly  con- 
geals and  later  on  can  be  readily  detached  from  the  cru- 
cible. The  dissolution  of  the  melt  in  hydrochloric  acid 


100  THE   EXAMINATION   OF   SOILS. 

and  separation  of  silica  are  effected  in  the  manner  given 
on  p.  97.  In  the  filtrate  from  the  silica  the  alumina, 
ferric  oxide,  oxide  of  manganese,  calcareous  earth  and 
magnesia  are  determined  according  to  the  methods  pre- 
viously given.  Such  substances  as  titanic  acid,  sulphu- 
ric acid,  chlorine  and  phosphoric  acid  which  occur  only 
in  small  quantities  in  the  soil  cannot  be  determined  with 
sufficient  accuracy  in  the  quantity  used,  and  therefore, 
need  not  to  be  noticed. 

If  the  substance  used  is  free  from  organic  or  carbon- 
aceous matter,  the  content  of  ferrous  oxide  may  be  de- 
termined by  disintegrating  a  special  sample  of  the  total 
soil  with  sulphuric  acid  in  a  closed  glass  tube  (p.  84), 
separating  the  residue  from  the  fluid  by  filtering  in  a 
current  of  carbonic  acid  and  determining  the  ferrous 
oxide  in  the  fluid  by  titration  with  potassium  perman- 
ganate solution  (p.  89). 

6.  Disintegration  with  fluoric  add. — Disintegration 
with  fluoric  acid  is  best  effected  by  simultaneously  com- 
bining with  it  a  determination  of  loss  by  ignition.  For 
this  purpose  1  to  2  grammes  of  the  finely  pulverized 
substance  dried  at  212°  F.  are  first  gently  heated  in  a 
platinum  crucible  and  then  vigorously  ignited  over  the 
blast  lamp.  After  cooling  in  the  desiccator  tire  loss  by 
ignition  is  determined  by  weighing.  The  mass  which 
is  slagged  together,  and,  in  the  presence  of  lime,  often 
fused,  is  moistened  with  distilled  water  and  then  strong 
fluoric  acid  is  poured  over  it.  The  crucible  is  now  cov- 
ered, and  after  placing  in  it  a  small  platinum  spatula  of 
stout  platinum  wire  to  the  handle  of  which  a  cork  is 
secured,  allow  the  acid  to  act  upon  the  substance  2  or  3 
days,  stirring  frequently,  until  a  pasty  mass  is  formed. 


PLANT-NOURISHING   SUBSTANCES.  101 

Then,  with  frequent  stirring,  evaporate  the  contents  of 
the  crucible  to  dryness  upon  the  water  bath,  in  order 
to  expel  the  silica  as  silicon-fluoride.  The  crucible 
being  held  obliquely,  the  dry  residue  in  it  is  moistened, 
with  concentrated  sulphuric  acid  in  order  to  convert  the 
fluorides  into  sulphates.  The  excess  of  sulphuric  acid 
is  expelled  by  heating  the  crucible  placed  obliquely  so 
that  a  very  small  flame  acts  upon  it  from  the  edge ;  this 
is  done  to  prevent  the  substance  from  scattering.  When 
the  mass  is  dry,  it  is  dissolved  from  the  crucible  by 
means  of  hydrochloric  acid  and  water,  and  with  the  aid 
of  a  wrash  bottle  brought  into  a  beaker.  When  covered 
with  a  watch-crystal  and  boiled  continuously,  the  mass 
should  dissolve  entirely  clear.  Now,  for  the  oxidation 
of  the  ferrous  oxide,  add  some  bromine  water,  boil  the 
fluid  until  the  excess  of  bromine  is  completely  expelled 
and-  determine  the  aluminia,  oxides  of  iron  and  manga- 
nese, calcareous  earth,  magnesia,  potash,  and  soda. 


VII. 

DETERMINATION  OF  THE  PLANT-NOURISHING 
SUBSTANCES. 

IN  the  determination  of  the  plant-nourishing  sub- 
stances we  may  proceed  either  by  separately  determining 
the  nourishing  substances  at  the  time  present  and  avail- 
able in  the  soil,  and  those  which  only  gradually  become 
available,  or  by  determining  from  the  start  the  sum-total 
of  those  already  present  and  of  those  which  in  a  con- 
ceivable space  of  time  may  become  active  by  processes  of 


102  THE   EXAMINATION   OF   SOILS. 

weathering  and  decay.  In  the  first  case  the  processes 
taking  place  in  nature  will  have  to  be  imitated  as  closely 
as  possible,  this  being  approximately  effected  by  success- 
ively treating  the  soil  with  agents  constantly  increasing 
in  strength. 

A.  Determination  of  the  plant-nourishing  substances  in 
soil  extractions. — The  above-indicated  requirements  are 
best  fulfilled  by  the  following  fluids,  which  in  very  com- 
prehensive soil  investigations  are  successively  allowed  to 
act  upon  the  soil : — 

1.  Cold  distilled  water.  2.  Cold  distilled  water,  one- 
quarter  saturated  with  pure  carbonic  acid.  3.  Cold 
concentrated  hydrochloric  acid  (specific  gravity  1.15). 
4.  Boiling  concentrated  hydrochloric  acid. 

If  only  the  sum-total  of  the  plant-nourishing  sub- 
stauces  present  and  of  those  which  will  shortly  become 
active  is  to  be  determined,  the  soil  is  directly  treated 
with  boiling  concentrated  hydrochloric  acid,  the  other 
extractions  being  omitted. 

I.  Extraction  of  the  soil  with  cold  distilled  water. — By 
treating  the  soil  with  cold  distilled  water,  only  the  con- 
stituents soluble  in  water  can,  of  course,  be  extracted. 
Such  constituents,  independent  of  humus  substances,  are 
chiefly  chlorides,  sulphates,  and  nitrates  of  calcium, 
magnesium,  potassium,  and  sodium.  Hence,  only  these 
substances  will  have  to  be  determined. 

The  aqueous  extract  of  the  soil  is  prepared  as  fol- 
lows :  Bring  into  a  glass  flask  of  2  liters  capacity,  and 
which  can  be  closed  with  a  rubber  cork,  500  grammes 
of  air-dry  fine  soil  (less  than  2  millimeters  in  diameter), 
and  pour  over  it  1000  cubic  centimeters  of  distilled 
water,  less  the  volume  which  would  escape  in  drying 


PLANT-XOURISHIXG   SUBSTANCES.  103 

500  grammes  of  fine  soil  at  212°  F.  For  this  purpose 
determine  at  the  same  time  the  water  escaping  from 
about  20  grammes  of  the  same  fine  soil  when  continu- 
ously heated.  First  weigh  the  air-dry  sample  in  a 
weighing-flask,  then  spread  it  out  in  as  thin  a  layer  as 
possible  upon  a  watch-crystal,  and  heat  it  for  2  hours  at 
212°  F.  in  a  drying-chamber.  Now,  with  the  aid  of  a 
brush  bring  the  dried  substance,  while  hot,  into  the 
heated  weighing-flask,  close  the  latter  hermetically,  and 
let  it  cool  in  the  weighing  room.  The  determination  of 
the  water  escaped  at  212°  F.  can  only  be  relied  on 
when,  after  repeated  drying  and  again  weighing,  no 
noticeable  difference  in  weight  is  obtained.  The  quan- 
tity of  soil  weighed  out  for  extraction  is  allowed  to 
remain  in  contact  with  the  water  for  two  days,  being 
in  the  meanwhile  frequently  shaken,  and,  after  settling, 
the  supernatant  fluid  is  drawn  off  by  means  of  a  siphon 
provided  with  a  suction  pipe.  The  fluid  is  then  filtered 
through  a  dry  filter  into  two  measuring  flasks,  one  of 
500  and  the  other  of  300  cubic  centimeters  capacity. 

1.  Determination  of  the  bases  in  the  aqueous  extract. — 
Evaporate  the  300  cubic  centimeters  of  the  aqueous  ex- 
tract ;  which  correspond  to  150  grammes  of  fine  soil 
dried  at  212°  F.,  in  a  small  weighed  platinum  dish  upon 
the  sand  bath,  dry  the  residue  at  212°  F.,  and  weigh  it 
after  cooling  in  the  desiccator.  Now,  gently  ignite  the 
platinum  dish,  and  after  cooling  in  the  desiccator,  weigh 
it  again.  By  this  means  the  sum-total  of  the  substances 
dissolved  in  water,  as  well  as  the  incombustible  matter 
contained  therein,  is  learned.  If  the  latter  is  less  than 
0.5  gramme,  the  separation  of  the  alkalies  and  alkaline 
earths  cannot  be  accurately  carried  out,  on  account  of 


104  THE   EXAMINATION   OF   SOILS. 

the  small  quantity  which  would  have  to  be  weighed. 
It  is,  therefore,  best  to  repeat  the  aqueous  extraction 
with  such  a  quantity  of  fine  soil  that  the  amount  of 
extract  intended  for  the  determination  of  the  bases  con- 
tains at  least  1  to  0.5  gramme  of  dissolved  substances. 
The  residue  obtained  by  igniting  is  dissolved  with  the 
addition  of  some  hydrochloric  acid  in  distilled  water 
and  filtered  in  case  traces  of  silica  are  found.  The  fluid 
is  then  heated  to  boiling,  and  traces  of  iron  and  alumina, 
which,  as  a  rule,  reach  the  fluid  only  by  turbid  filtering, 
are  precipitated  with  ammonia.  In  the  filtrate  the  cal- 
careous earth  is  precipitated  in  the  manner  given  on  pp.  67 
and  68.  The  filtrate  of  calcium  oxalate  is  evaporated  in  a 
capacious  platinum  crucible,  and,  after  drying,  moderately 
ignited  to  expel  the  excess  of  sal  ammoniac.  The  pro- 
cess of  drying  can  be  essentially  accelerated  by  constant 
stirring  with  a  platinum  spatula.  The  residue  is  taken 
up  with  a  few  drops  of  water,  brought  into  a  small 
beaker,  and  the  solution,  if  not  clear,  is  again  filtered 
through  a  small  filter. 

The  magnesia  is  now  precipitated  by  ammonium  car- 
bonate, the  solution  of  which  is  prepared  as  follows : 
Dissolve  230  grammes  of  sublimed  sesquicarbonate 
of  ammonia  in  180  cubic  centimetres  of  ammonia  of 
0.92  specific  gravity,  and  add  sufficient  water  to  make 
the  volume  of  the  fluid  exactly  1  liter.  This  solution 
must  be  added  in  considerable  excess.  If  much  mag- 
nesia is  present,  a  voluminous  precipitate  is  at  first 
formed  which,  on  stirring  is,  however,  completely  re- 
dissolved.  The  fluid  is  now  allowed  to  stand  quietly 
for  twenty-four  hours,  during  which  time  a  fine  crystal- 


PLANT-NOURISHING   SUBSTANCES.  105 

line  precipitate  consisting  of  ammonium  magnesium 
carbonate  is  formed.  This  salt  is  filtered  off,  washed 
with  ammonium  carbonate  solution,  and  when  a  drop 
running  off  leaves  no  residue  when  evaporated  upon  a 
platinum  sheet,  dried  at  212°  F.  in  the  drying  chamber. 
The  precipitate,  together  with  the  filter,  is  heated  in  the 
platinum  crucible,  and  when  the  filter  is  carbonized, 
strongly  ignited,  the  crucible  being  placed  in  an  oblique 
position.  The  precipitate,  which  consists  of  magnesia, 
must  be  perfectly  white  after  ignition. 

The  filtrate  from  the  ammonium  magnesium  carbonate 
contains  the  alkalies.  It  is  brought  into  a  capacious 
platinum  dish,  which  is  covered  with  a  watch-crystal  and 
heated  upon  the  water-bath.  As  soon  as  the  decomposi- 
tion of  the  ammonium  carbonate  begins,  the  flame  is 
made  somewhat  smaller  to  prevent  the  fluid  from  foam- 
ing over,  and  the  latter  is  then  heated  until  no  more 
bubbles  of  carbonic  acid  escape.  The  watch-crystal  is 
then  removed  and  rinsed  off  with  distilled  water,  and 
the  fluid  evaporated  in  a  smaller  weighed  platinum  dish 
upon  the  water-bath.  The  residue  is  moistened  with  a 
few  drops  of  hydrochloric  acid,  again  evaporated,  and 
the  covered  platinum  dish  dried  in  the  drying  chamber 
at  a  temperature  gradually  raised  to  392°  F.  By  this 
means  loss  by  the  decrepitation  of  the  water  inclosed 
in  the  common  salt  while  igniting  the  salt  in  the  pla- 
tinum dish  is  avoided.  The  platinum  crucible  is  only 
slightly  ignited,  the  alkaline  chlorides  being  volatile  at  a 
strong  red  heat.  After  cooling  in  the  desiccator  the 
platinum  crucible  is  weighed.  In  this  manner  the  sum 
total  of  the  chlorides  of  potassium  and  sodium  are 
learned. 


106 


THE    EXAMINATION    OF   SOILS. 


Fig.  15. 


To  separate  the  potassium  from  the  sodium,  take  up 
the  chlorides  with  a  few  drops 
of  water  and  add  solution  of 
platinum  chloride  in  excess. 
Now,  in  an  atmosphere  free 
from  ammonia,  evaporate  the 
fluid  on  a  covered  water-bath 
(Fig.  15)  until  it  possesses  a 
syrupy  consistency  and  the 
platinum  chloride  commences 
to  separate  in  it  in  a  crystal- 
line form.  After  cooling,  add 
one  part  of  a  mixture  of  55 
cubic  centimeters  of  absolute 
alcohol  and  15  cubic  centi- 
meters of  ether,  and  allow 
the  fluid  to  stand  under  a 
glass-bell  for  12  hours,  stir- 
ring it  several  times  in  the 
mean  while.  Then  filter  it  through  a  weighed  filter  and 
wash  the  precipitate  remaining  upon  the  filter  with  some 
alcohol  containing  ether  until  the  fluid  running  off  is  no 
longer  colored. 

A  greater  number  of  weighed  filters  may  be  best  pre- 
pared as  follows :  Treat  several  filters  first  with  hydro- 
chloric acid,  and,  after  thoroughly  sweetening  them  with 
distilled  water,  dry  them  continuously  at  212°  F.  in  the 
drying  closet.  Then  bring  them  hot  into  a  weighing 
flask,  also  heated  to  212°  F.,  and  weigh  the  flask  after 
cooling.  By  successively  taking  out  the  filters,  and  each 
time  rcweighing  the  flask,  the  weights  of  the  filters  are 
obtained,  which  are  best  noted  upon  them  with  a  pencil. 


PLANT-NOURISHING   SUBSTANCES.  107 

The  precipitate  of  potassium  platinum  chloride  is 
thoroughly  washed  upon  the  filter,  then  dried  at  212°  F. 
brought  hot,  together  with  the  filter,  into  a  weighing 
tube  aud  weighed  after  cooling.  By  deducting  the 
weight  of  the  weighing  tube,  and  of  the  filter,  from  the 
weight  last  obtained,  the  quantity  of  potassium  platinum 
chloride  present  is  obtained.  To  obtain  the  equivalent 
quantity  of  potassium  multiply  by  the  factor  0.193. 

Instead  of  weighing  the  potassium  platinum  chloride 
upon  a  weighed  filter,  the  salt  may  be  decomposed  and 
the  potassium  determined  from  the  platinum  obtained. 
In  this  case  add  to  the  precipitate  in  the  filter  some  pure 
oxalic  acid  and  ignite  the  mass  in  a  weighed  porcelain 
crucible  provided  with  a  cover ;  finally,  in  order  to 
reduce  all  the  platinum,  conduct  a  current  of  water  upon 
the  crucible  and  allow  the  substance  to  cool  in  it.  To 
remove  the  potassium  chloride,  the  platinum  is  washed 
with  water  by  repeated  decantation,  and,  after  drying 
and  again  igniting,  weighed.  To  obtain  the  equivalent 
quantity  of  potassium,  multiply  the  platinum  by  the 
factor  0.477. 

To  obtain  the  sodium,  calculate  the  potassium  to 
potassium  chloride  by  multiplying  by  the  factor  1.584, 
deduct  the  potassium  chloride  fiom  the  sum  of  the 
chlorides,  and  multiply  the  sodium  chloride  thus  ob- 
tained by  the  factor  0.530. 

If  many  sulphates  are  present  among  the  soil-salts 
soluble  in  wrater,  which  may  be  the  case  with  soils  very 
rich  in  gypsum,  it  is  better,  after  precipitating  the  mag- 
nesia with  ammonium  carbonate  and  evaporating  the 
solution,  to  add  a  few  drops  of  sulphuric  acid  and  then 
ignite  strongly  in  a  weighed  platinum  dish.  In  doing 


108  THE   EXAMINATION   OF   SOILS. 

this,  a  small  piece  of  ammonium  carbonate  has  to  be  held 
by  means  of  a  pair  of  tweezers  in  the  dish  in  order  to 
convert  the  acid  alkaline  sulphates  into  neutral.  The 
alkaline  sulphates  being  very  refractory,  ignition  may 
finally  be  carried  to  an  initial  red  heat.  After  weighing, 
dissolve  the  sulphates  in  water,  compound  them  with 
platinum  chloride,  and  evaporate  the  solution  to  a 
syrupy  consistency  upon  the  water-bath.  Now  dis- 
solve the  mass,  according  to  Finkeuer's  directions,  in  a 
mixture  which,  for  30  cubic  centimeters  of  hydrochloric 
acid,  contains  150  cubic  centimeters  of  absolute  alcohol 
and  35  cubic  centimeters  of  anhydrous  ether.  When 
the  whole  has  stood  for  one  hour,  bring  the  precipitate 
upon  a  weighed  filter  and  wash  it  with  a  mixture  of 
hydrochloric  acid,  alcohol,  and  ether,  in  the  above-men- 
tioned proportions  until  the  fluid  runs  off  clear.  Then, 
to  remove  the  hydrochloric  acid,  wash  with  alcohol  con- 
taining ether,  dry  the  filter  at  212°  F.  and  weigh  it, 
together  with  the  potassium  platinum  chloride  upon  it, 
in  the  manner  given  on  p.  107. 

To  determine  the  sodium  in  this  case,  multiply  the 
potassium  by  the  factor  1.851,  deduct  the  potassium 
sulphate  thus  obtained  from  the  total  of  the  sulphates, 
and  multiply  the  remaining  sodium  sulphate  by  the 
factor  0.437. 

2.  Determination  of  the  acids  in  the  aqueous  extract, 
a.  Determination  of  chlorine. — If  the  aqueous  extract  of 
the  soil  contains  no  sulphuric  acid  or  only  a  trace  of  it, 
which  is  recognized  by  filtering  oif  a  small  sample  of  the 
supernatant  water  and  compounding  the  clear  filtrate 
with  some  nitric  acid  and  barium  chloride  solution,  the 


PLANT-NOURISHING   SUBSTANCES.  109 

chlorine  may  first  be  determined.  Otherwise  the  sul- 
phuric acid  is  first  precipitated. 

Compound  the  500  cubic  centimeters  of  aqueous  ex- 
tract mentioned  on  p.  102  with  a  small  quantity  of  pure 
sodium  carbonate  and  evaporate  to  about  100  cubic  cen- 
timeters. In  case  anything  has  been  separated,  the 
fluid  is  filtered,  compounded  with  nitric  acid  and  heated. 
From  the  boiling  hot  solution,  the  chlorine  is  precipi- 
tated with  silver  nitrate  solution,  stirring  constantly 
with  a  glass  rod,  until  the  precipitate  balls  together  and 
the  fluid  becomes  entirely  clear.  The  silver  chloride 
thus  obtained  is  filtered  off,  washed  with  hot  water, 
dried  at  212°  F.,  and,  after  detaching  it  as  much  as  pos- 
sible from  the  filter,  brought  into  a  previously  weighed 
porcelain  crucible.  The  filter  is  incinerated  by  itself 
upon  the  lid  of  the  crucible  and  then  added  to  the  silver 
chloride  in  the  crucible.  Since  by  incineration  the  par- 
ticles of  silver  chloride  adhering  to  the  filter  have  been 
partially  reduced  to  silver,  saturate  the  filter  ash  with  a 
drop  of  nitric  acid  which  is  allowed  to  drop  into  the 
crucible  from  a  glass  rod.  Then  heat  somewhat  in  order 
to  dissolve  the  silver  and  add  one  drop  of  hydrochloric 
acid.  The  crucible  is  then  heated,  first  very  moderately, 
and  then  gradually  more  strongly,  and,  when  no  more 
vapors  of  nitrous  acid  escape,  so  strongly  that  the  silver 
chloride  fuses  together  to  a  regulus.  Now  allow  the 
crucible  to  cool  in  the  desiccator,  then  weigh  it  and  de- 
duct the  filter  ash.  The  quantity  of  the  silver  chloride 
found  multiplied  by  the  factor  0.247  gives  the  quantity 
of  chlorine  in  the  aqueous  extraction  (500  cubic  cen- 
timeters equal  to  250  grammes  of  soil  dried  at  212°  F.). 

6.  Determination  of  sulphuric  acid. — If  the  aqueous 


110  THE    EXAMINATION   OF   SOILS. 

extract  of  the  soil  contains  sulphate,  the  sulphuric  acid, 
as  previously  mentioned,  is  precipitated  before  the  chlo- 
rine. Evaporate  the  500  cubic  centimeters  mentioned 
on  p.  107,  to  100  cubic  centimeters,  filter,  and  into  the 
boiling  hot  solution  precipitate  the  sulphuric  acid  with 
barium  nitrate  solution. 

Since  the  heavy  precipitate  consisting  of  barium  sul- 
phate generally  carries  down  with  it  other  salts,  it  must 
be  again  digested  for  some  time  with  dilute  hydrochloric 
acid,  after  being  washed  with  hot  water,  dried  and 
weighed.  Then  pour  the  supernatant  hydrochloric  acid 
through  a  very  small  filter  and  wash  the  precipitate, 
without  taking  it  from  the  crucible,  by  decanting  with 
hot  water.  Evaporate  the  filtrate  and  wash-water  nearly 
to  dryness  in  a  platinum  dish  and  bring  the  precipitate 
thereby  separated  also  upon  the  filter.  After  washing, 
drying  and  incinerating  the  latter,  add  it  to  the  other 
precipitate  in  the  platinum  crucible  and  ignite  at  a 
moderate  red  heat.  Weigh  the  crucible  after  cooling  in 
the  desiccator. 

The  barium  sulphate  multiplied  by  the  factor  0.343 
will  give  the  weight  of  sulphuric  acid  (SO3)  present. 

c.  Determination  of  nitric  acid. — Pour  over  1000 
grammes  of  the  air-dry  fine  soil  2000  cubic  centimeters 
of  distilled  water  less  the  quantity  of  water  calculated 
from  the  determination  of  the  hygroscopic  water  which 
would  escape  from  1000  grammes  of  soil  in  drying  at 
212°  F.  Allow  the  soil  to  remain  in  contact  with  the 
water  for  forty-eight  hours,  shaking  frequently.  Then 
remove  the  supernatant  clear  fluid  by  means  of  a  siphon 
provided  with  a  suction-tube,  and  filter  it  through  a  dry 
filter  into  a  liter-flask.  One  liter  of  this  soil  extract  is 


PLANT-NOURISHING   SUBSTANCES.  Ill 

equal  to  500  grammes  of  soil  dried  at  212°  F.  Com- 
pound this  quantity  of  aqueous  extract  with  a  small 
quantity  of  pure  sodium  carbonate  and  evaporate  it  to 
about  100  cubic  centimeters  upon  the  water-bath.  Any 
precipitate  formed  is  filtered  off,  washed,  and  the  filtrate 
again  evaporated  to  100  cubic  centimeters. 

For  the  determination  of  the  nitric  acid  in  these  100 
cubic  centimeters,  it  is  best  to  use  the  method  originated 
by  Schoening  and  variously  modified  by  T.  Schulze  as 
well  as  by  Fruehling  and  Grouven,  Reichardt,  and  Tie- 
mann.  It  is  based  upon  the  reduction  of  the  nitric  acid 
by  a  solution  of  ferrous  chloride  in  hydrochloric  acid  to 
nitric  oxide,  expelling  the  latter  by  boiling  and  collect- 
ing it.  The  chemical  process  takes  place  according  to 
the  following  equation  : — 

6FeCl2  +  2KNO3  +  8HC1  =  4H2O  +  2KC1  -f 
3Fe2Cl6  4-  2NO;  or  :  6FeCl2  +  2HNO3  +  6HC1  = 
4H2O+3Fe2Cl6  +  2NO. 

This  method  can  be  especially  recommended,  since  the 
accuracy  of  the  result  is  not  in  the  least  impaired  even 
by  the  presence  of  dissolved  humus  constituents. 

a.  Tiemann's  modification  ofSchloesing-Schulze's  method 
for  the  determination  of  nitric  acid. — Tiemann's  modifica- 
tion has  the  advantage  of  yielding  very  accurate  and 
reliable  results  with  the  use  of  an  apparatus  dis- 
tinguished for  simplicity. 

The  aqueous  extract  evaporated  to  100  cubic  centi- 
meters is  brought  into  a- glass  flask,  A  (Fig.  16),  of  one- 
half-liter  capacity.  It  is  closed  by  a  doubly  perforated 
rubber  cork.  Two  glass  tubes  bent  in  the  shape  of  a 
knee  fit  accurately  into  the  perforations  of  the  rubber 
cork.  The  tube,  c  6  a,  is  at  a,  drawn  out  into  not  too 


112 


THE   EXAMINATION   OF   SOILS. 


fine  a  point  and  projects  about  2  centimeters  below  the 
rubber  cork,  while  efgis  exactly  even  with  the  lower 
surface  of  the  cork.  Both  these  tubes  are  connected  by 
means  of  thin  black  rubber  tubing  with  the  tubes,  c  d 


and  g  h.  The  rubber  tubing  can  be  hermetically  closed 
by  two  strong  clips,  c  and  g.  The  end  of  the  tube  g  h 
enters  the  so-called  crystallizing  glass  dish,  B,  and  pro- 
jects with  the  point,  which  is  bent  upwards  and  covered 
with  rubber  tubing  2  to  3  centimeters  into  the  measur- 
ing tube,  C.  The  latter  is  graduated  into  tenths  of  cubic 
centimeters,  and,  like  the  glass  dish,  B,  is  filled  with 
thoroughly  boiled  10  per  cent,  soda  lye  prepared  by  dis- 
solving 12.9  parts  of  caustic  soda  in  100  parts  of  water. 
The  fluid  to  be  examined  for  a  content  of  nitric  acid 
is  first  boiled  for  one  hour,  the  tubes  being  at  first  left 


PLANT-XOURISHIXG   SUBSTANCES.  113 

open  and  without  g  h  dipping  into  the  dish  S}  in  order 
to  expel  the  air  from  the  flask  A  by  aqueous  vapor. 
The  end  of  the  tube  efgh  is  then  brought  into  the 
caustic  soda  dish,  without,  however,  dippftig  in  the 
measuring  tube,  and  the  aqueous  vapors  are  allowed  to 
escape  partially  through  the  soda  lye  and  partially 
through  the  tube  abed.  After  a  few  minutes,  the  tube 
is  pressed  together,  at  g,  with  the  fingers;  and  when  all  the 
air  has  been  expelled,  the  soda  lye  will  reascend  in  the 
vacuum  of  the  tube  g  h,  which  is  recognized  by  a  gentle 
blow  on  the  fingers.  If  this  is  the  case,  the  tube  behind 
the  place  pressed  together  is  closed  with  the  clip  g,  and 
the  vapors  are  allowed  to  escape  through  abed.  The 
fluid  is  kept  boiling  until  evaporated  to  10  cubic  centi- 
meters. The  gas  flame  is  now  removed,  the  rubber 
tubing  immediately  closed  at  c,  with  the  clip,  and  the  tube 
c  d  filled  with  thoroughly  boiled  water.  Should  an  air 
bubble  remain  at  c,  it  is  removed  by  pressing  with  the 
finger. 

The  measuring  tube  is  now  filled  with  thoroughly  boiled 
soda  lye,  and,  after  closing  the  opening  with  the  thumb 
so  that  no  air  bubbles  can  enter,  the  tube  is  inverted  and 
immersed  over  the  lower  end  of  the  tube  g  h  into  the 
soda  lye. 

When  the  tubes  c  and  g  are  pressed  together  by  the 
external  pressure  of  air,  the  nearly  saturated  solution  of 
ferrous  chloride  or  ferrous  sulphate  compounded  with 
some  hydrochloric  acid  is  brought  into  a  beaker  on  the 
upper  portion  of  wrhich  20  cubic  centimeters  are  divided 
off  by  two  strips  of  paper  pasted  on  the  outside.  An- 
other beaker  is  filled  with  concentrated  hydrochloric 
acid.  Now  dip  the  tube  c  d  into  ferrous  chloride  solution, 


114  THE    EXAMINATION   OF   SOILS. 

and,  after  opening  the  clip  c,  allow  15  to  20  cubic 
centimeters  to  run  into  the  flask.  Then  dip  the  tube  e  d 
into  the  concentrated  hydrochloric  acid  and  let  a  small 
quantity  of  it  rise  twice  until  all  the  ferrous  chloride  is 
rinsed  out  of  the  tube  abed.  At  6  a  small  bubble  of 
hydrochloric  acid  is  frequently  formed,  which  completely 
disappears  on  heating  the  flask.  Now  heat  the  flask 
very  moderately  until  the  rubber  tubings  begin  to  swell 
up  somewhat ;  then  substitute  the  finger  for  the  clip  at 
g,  and,  as  soon  as  the  gas-pressure  becomes  somewhat 
stronger,  allow  the  nitric  oxide,  expelled  from  the  solu- 
tion by  heating,  to  pass  over  into  the  measuring  tube. 
The  boiling  of  the  fluid  is  continued  until  an  increase  of 
the  volume  of  gas  in  the  measuring  tube  is  no  longer 
perceptible.  By  the  vigorous  absorption  of  hydro- 
chloric acid  gas  by  the  soda  lye,  a  crackling  noise  is 
made,  but  the  end  of  the  tube  g  h  being  protected,  as 
previously  mentioned,  by  rubber  tubing,  its  fracture 
need  not  be  feared. 

When  the  operation  is  finished,  the  tube  g  h  is  re- 
moved from  the  dish,  the  measuring  tube  closed  beneath 
the  soda  lye  with  the  thumb,  and,  after  shaking  it, 
together  with  the  soda  lye  still  in  it,  in  order  to  remove 
any  traces  of  hydrochloric  acid,  immerse  it  in  a  large 
glass  cylinder  filled  with  water  of  59°  to  64°  F. 

The  volume  of  nitric  oxide  can  be  read  off  after 
twenty  minutes.  For  this  purpose  immerse  the  measur- 
ing tube  so  far  into  the  water  of  the  cylinder  that  the 
fluid  in  the  measuring  tube  is  at  the  same  level  with  the 
fluid  outside  of  it.  In  this  case  the  nitric  oxide  is  under 
the  prevailing  atmospheric  pressure  as  indicated  by  the 
barometer. 


PLANT-NOURISHING  SUBSTANCES.  115 

Before  reading  off  the  volume  of  gas  the  measuring 
tube  should  be  placed  as  vertically  as  possible.  In 
reading  off  the  volume  of  gas,  the  centre  of  the  dark 
zone  formed  by  the  water  drawing  up  on  the  glass  is 
taken  as  the  actual  surface  of  the  water,  and  the  quan- 
tity of  nitrogen  evolved  noted  in  whole  and  tenths  of 
cubic  centimeters. 

The  volume  of  every  gas  measured  over  water,  l>ence 
in  a  moist  state,  is  dependent  on  the  temperature  of  the 
surroundings,  the  pressure  of  the  atmosphere  and  the 
tension  of  the  aqueous  vapor.  Hence,  in  reading  off 
the  volume  of  gas,  the  temperature  of  the  water  in  the 
cylinder  is  noted  as  well  as  the  height  of  the  barometer, 
and  the  volume  is  calculated  with  regard  to  the  tension 
of  aqueous  vapor  at  0°  C.  and  a  pressure  of  760  milli- 
meters of  mercury.  The  condition  in  which  a  dry 
volume  of  gas  is,  at  0°  C.,  and  a  pressure  of  760  milli- 
meters is  designated  as  the  normal  condition. 

According  to  Mariotte's  law,  the  volume  of  gas  is  in- 
versely as  the  pressure,  and  since  the  expansion  of  a  gas 
by  heat  amounts  for  each  degree  C.  to  ^73  of  the  volume 
it  occupies  at  0°  C.,  it  follows,  that  in  calculating  the 
volume  of  gas  to  the  normal  state,  the  pressure  exercised 
by  the  moist  state  must  be  deducted  from  the  height  of 
the  barometer. 


~  (273  +  *).760 

In  this  formula  Vo  means  the  volume  of  gas  at  the 
normal  temperature  (0°C.),  Fthe  volume  of  gas  read 
off  at  the  height  of  the  barometer  B,  and  the  tempera- 
ture t,  while/  indicates  the  tension  of  the  aqueous  vapor 
in  the  millimeters  of  pressure  of  mercury  at  1°  0. 


116 


THE   EXAMINATION   OF   SOILS. 


The  tension  of  the  aqueous  vapor  is  found  from  the 
following  table : — 


Tension  in 

Tension  in 

Tension  in 

Tempera- 
ture, C. 

millimeters 
of  pressure  of 

Tempera- 
ture, C. 

millimeters 
of  pressure  of 

Tempera- 
ture, C. 

millimeters 
of  pressure  of 

mercury. 

mercury. 

mercury. 

0° 

4.5 

9° 

8.5 

18° 

15.3 

1 

4.9 

10 

9.1 

19 

16.3 

2 

5.2 

11 

9.7 

20 

17.4 

3 

5  6 

12 

10.4 

21 

18.5 

4 

6.0 

13 

11.1 

22 

19.6 

5 

6.5 

14 

11.9 

23 

20.9 

6 

6.9 

15 

12.7 

24 

22.2 

7 

7.4 

16 

13.5 

25 

23.5 

8 

8.0 

17 

14.4 

26 

25.0 

To  calculate  the  nitric  oxide  found  to  nitric  acid  in 
grammes,  multiply  the  number  of  cubic  centimeters  of 
nitric  oxide  calculated  to  the  normal  state  by  the  factor 
0.002413. 

6.  W.  Wolf's  method  of  determining  the  nitric  acid  by 
means  of  zinc  in  alkaline  solution. — This  method,  which 
is  distinguished  by  simplicity  and  accuracy,  is  based 
upon  the  reduction  of  nitrates  to  ammonia  gas  by  zinc 
in  alkaline  solution  through  the  hydrogen  formed 
thereby. 

Since  the  presence  of  humus  substances  impairs  the 
experiment,  the  1000  cubic  centimeters  of  aqueous  ex- 
tract (p.  110)  to  be  used  for  this  purpose  must,  in  case 
they  show  a  brown  coloration,  be  boiled  with  the  addi- 
tion of  some  pure  milk  of  lime,  whereby  the  humus 
substances  are  separated.  After  filtering  the  latter  off, 
the  excess  of  lime  in  the  filtrate  is  precipitated  by  the 
introduction  of  pure  carbonic  acid  and,  after  again  filter- 
ing, the  filtrate  is  evaporated  to  100  cubic  centimeters. 


PLANT-NOURISHING   SUBSTANCES.  117 

Now  bring  the  fluid  into  a  glass  flask  of  about  ^  liter 
capacity  and  compound  it  with  soda  lye,  so  that  it  con- 
tains about  14  grammes  of  soda.  Close  the  flask  quickly 
with  a  perforated  rubber  cork  and  insert  a  cylindrical 
funnel  tube  in  the  perforation.  Close  the  top  of  the 
funnel  tube  with  a  rubber  cork  through  which  passes  an 
open  glass  tube.  Bring  into  the  funnel  tube  glass  beads 
moistened  with  hydrochloric  acid,  so  that  the  hydrogen 
evolved  can  escape  free  from  ammonia.  The  evolution 
of  hydrogen  is  induced  by  placing  a  spiral  of  sheet  zinc 
and  sheet  iron  soldered  together  in  the  fluid.  This 
gas  is  allowed  to  act  upon  the  nitrates  4  to  5  hours  at 
an  ordinary  temperature.  The  rubber  cork  is  then 
carefully  withdrawn,  its  lower  surface  rinsed  off  and, 
after  rinsing  the  hydrochloric  acid  adhering  to  the  glass 
beads  into  the  flask  by  means  of  a  wash-bottle,  the 
spiral,  which  must  also  be  rinsed  off,  is  taken  from  the 
fluid  with  the  aid  of  tweezers.  Now  quickly  add  some 
soda  lye  to  the  fluid,  and  connect  the  flask  by  means  of 
the  rubber  cork  with  a  glass  receiver,  in  the  other  end  of 
which  a  knee-shaped  tube  is  inserted  through  a  rubber 
cork.  This  glass  tube  reaches  into  an  Erlenmeyer 
boiling  flask  containing  about  10  cubic  centimeters  of 
pure  dilute  hydrochloric  acid.  The  end  of  the  tube  in 
the  receiver  should  not  dip  into  the  fluid,  but  be  just  above 
its  surface.  Now  boil  the  fluid  which  contains  the  ni- 
trogen in  the  form  of  ammonia  until  one-half  of  it  has 
been  distilled  into  the  receiver. 

The  determination  of  the  ammonium  chloride  con- 
tained in  the  distillate  can  be  effected  in  various  ways  : 

1.  Determination  of  the  ammonium  chloride  as  am- 
monio-platinum  after  the  conversion  of  the  nitric  acid  into 


118  THE   EXAMINATION   OF   SOILS. 

ammonium  chloride. — The  above-mentioned  distillate, 
which  contains  the  sal  ammoniac  is  evaporated  to  a 
small  volume  upon  the  water-bath  and  compounded  in 
excess  with  pure  platinum  chloride  solution  free  from 
nitric  acid.  The  whole  is  then  evaporated  nearly  to 
dryness  upon  the  water-bath  and  a  mixture  of  2  vol- 
umes of  absolute  alcohol  and  1  of  ether  added.  The 
residue  remaining  undissolved,  constituting  a  heavy 
pale-yellow  powder,  is  brought  upon  a  filter  previously 
weighed  and  dried  at  257°  F.,  and  washed  with  alcohol 
containing  ether,  of  the  above-mentioned  composition. 
It  is  then  dried  at  257°  F.  and  weighed  in  a  tarred 
weighing  flask.  The  result  is  not  effected  by  a  darker 
color  of  the  precipitate. 

If  the  metallic  platinum  is  to  be  weighed,  it  is  only 
necessary  to  heat  the  ammouio-platinum  in  a  crucible 
covered  with  a  lid.  Heating  must,  however,  be  effected 
very  gradually  as  otherwise  the  escaping  vapors  of  chlo- 
rine and  ammonium  chloride  might  readily  carry  away 
particles  of  platinum.  After  detaching  the  precipitate 
as  much  as  possible,  the  filter  is  incinerated  by  itself  arid 
then  added  to  the  mass.  To  obtain  the  equivalent  of 
nitric  acid,  multiply  the  ammonio-platinum  by  0.241,  or 
the  platinum  by  0.547. 

2.  Volumetric  determination  by  the  Knop-Wagner 
azotometer  of  the  nitrogen  in  the  ammonium  chloride  after 
converting  the  nitric  acid  into  ammonium  chloride. — This 
method  is  based  upon  the  process  that  a  sal  ammoniac 
solution  is  decomposed  by  sodium  bromide  solution, 
nitrogen  being  liberated :  3(BrONa)  +  2(NH4C1)  = 
3(BrNa)  +  3(OH2)  +.  2HC1  +  ZN. 

The  solution  of  sodium  bromide  is  prepared  as  fol- 


PLANT-XOURISHING   SUBSTANCES.  119 

lows:  Dissolve  100  grammes  of  caustic  soda  in  1250 
cubic  centimeters  of  distilled  water,  cool  the  solution 
and  add,  with  constant  shaking,  25  cubic  centimeters  of 
bromine.  This  lye  is  gradually  decomposed  by  light 
and  must,  therefore,  be  kept  in  a  dark  bottle.  Fifty 
cubic  centimeters  of  it  are  capable  of  evolving  130  to 
150  cubic  centimeters  of  nitrogen  from  sal  ammoniac 
solution. 

The  Knop- Wagner  azotometer  (Fig.  17)  is  arranged 
as  follows :  The  bottom  of  the  developing  vessel  is  ce- 
mented in  a  metallic  ring  and  loaded  with  lead.  It  is 
partitioned  off  into  divisions  by  a  glass  wall  not  reaching 
quite  to  the  top ;  one  of  these  divisions  is  filled  with 
sal  ammoniac  solution  and  the  other  with  bromine  lye. 
It  is  necessary  to  constantly  retain  a  determined  propor- 
tion of  volume  of  the  two  fluids.  Hence,  the  distillate 
mentioned  on  p.  117  is  evaporated  nearly  to  dryness  in 
a  porcelain  dish  and,  after  filling  a  pipette,  holding  10 
cubic  centimeters,  with  distilled  water,  a  few  drops  are 
added  to  dissolve  the  sal  ammoniac.  This  solution  is 
poured  through  a  long  funnel-tube  into  one  of  the  divis- 
ions of  the  developing  vessel,  the  porcelain  dish  and 
funnel-tube  being  rinsed  out  with  the  water  remaining 
in  the  pipette.  Into  the  other  division  50  cubic  cen- 
timeters of  bromine  lye,  prepared  according  to  the  direc- 
tions given  above,  are  introduced  by  means  of  a  pipette. 
The  developing  vessel  being  closed  with  a  rubber  cork, 
it  is  immersed  in  the  cooling  vessel  so  that  the  rubber 
cork  is  just  covered  with  water.  This  cooling  vessel,  as 
well  as  the  tall  glass  cylinder,  is  filled  with  cool  water 
of  the  same  temperature.  Through  the  rubber  cork  of 
the  developing  vessel  passes  a  glass  tube  provided  with 


120  THE   EXAMINATION   OF   SOILS. 

a  glass  stop-cock  which  is  connected  by  means  of  rubber 
tubing  with  the  graduated  glass  tube  in  the  cylinder. 

Fig.  17. 


The  glass  stop-cock  is  loosened  or  taken  out,  and  the 
communicating  tubes  inclosed  in  the  glass  cylinder  are 
filled  with  water  by  compressing  the  rubber  ball  pro- 
vided with  a  hole,  the  clip  being  opened  at  the  same 
time.  By  discharging  the  water  through  the  clip,  the 
lower  meniscus  of  the  surface  of  the  water  is  exactly 
brought  to  the  0  point  of  the  graduated  tube.  After  5 
minutes  the  glass  stop-cock  is  firmly  replaced,  but  so 
that  the  developing  vessel  remains  in  communication 
with  the  graduated  tube.  Now  wait  5  minutes,  and 


PLANT-NOURISHING   SUBSTANCES.  121 

then  observe  whether  the  surface  of  the  water  in  the 
graduated  tube  has  risen  in  consequence  of  the  contrac- 
tion of  the  air  due  to  cooling  off.  This  being  the  case 
the  glass  stop-cock  is  once  more  loosened,  then  firmly 
replaced  and,  after  5  minutes,  the  height  of  water  in  the 
graduated  tube  again  observed.  This  is  repeated  until 
the  water  level  remains  constant  at  the  0  point.  The 
developing  vessel  is  now  taken  from  the  cooling  cylinder 
and,  after  discharging  20  to  30  cubic  centimeters  of 
water  through  the  clip,  the  bromine  lye  is  gradually 
allowed  to  flow  into  the  sal  ammoniac  solution  by  in- 
clining the  developing  vessel.  The  evolution  of  nitro- 
gen is  promoted  by  swinging  the  glass.  The  glass  stop- 
cock is  now  closed,  and,  after  vigorously  shaking  the  de- 
veloping flask,  the  stop-cock  is  again  opened  and  the 
developed  nitrogen  allowed  to  pass  into  the  graduated 
tube,  this  operation  being  repeated  three  times.  The 
developing  vessel  is  now  replaced  in  the  cooling  cylinder 
and  brought  into  communication  with  the  graduated 
tube  by  means  of  the  glass  stop-cock.  After  15  minutes 
it  has  acquired  the  same  temperature  as  before,  and  suffi- 
cient water  is  either  discharged  or  added  through  the 
clip  to  bring  the  level  in  the  two  communicating  tubes 
to  the  same  height.  Now  read  off  the  number  of  cubic 
centimeters  of  nitrogen  evolved,  the  temperature  indi- 
cated by  the  thermometer  iu  the  cylinder,  and  the  height 
of  the  barometer. 

Since  the  fluid  in  the  developing  vessel  has  absorbed 
a  not  inconsiderable  quantity  of  nitrogen,  it  has  to  be 
taken  into  calculation.  In  order  to  utilize,  for  this 
purpose,  the  following  table  by  Dietrich,  it  is  necessary 
always  to  use  exactly  10  cubic  centimeters  of  the  fluid 


122 


THE   EXAMINATION   OF   SOILS. 


to  be  examined  and  50  cubic  centimeters  of  bromine  lye 
of  the  above-mentioned  concentration,  since  the  quantity 
of  gas  absorbed  also  changes  with  the  concentration  and 
quantity  of  the  fluid. 

Dietrich's  table  for  the  absorption  of  nitrogen  in  60  cubic  centi- 
meters1 developing  fluid  (50  cubic  centimeters  of  bromine  lye 
and  10  cubic  centimeters  of  water),  with  a  specific  gravity  of 
the  lye  of  1.1,  and  such  a  strength  that  50  cubic  centimeters 
correspond  to  200  cubic  centimeters  of  nitrogen,  icith  an  evolu- 
tion of  1  to  100  cubic  centimeters  of  nitrogen. 


Evolved  ccm. 
Absorbed  ccm. 

1 
0.06 

2 
00.8 

3 
0.11 

4 
0.13 

5 
0.16 

6 
0.18 

7 
0.21 

8 
0.23 

9 
0.26 

10 
0.28 

Evolved  ccm. 
Absorbed  ccm. 

11 
0.31 

12 
0.33 

13 
0.36 

14 
0.38 

15 
0.41 

16 
0.43 

17 
0.46 

18 
0.48 

19 

0.51 

20 
0.53 

Evolved  cem. 
Absorbed  ccm. 

21 
0.56 

22 
0.58 

23 
0.61 

24 
0.63 

25 
0.66 

26 
0.68 

27 
0.71 

28 
0.73 

29 

0.76 

30 
0.78 

Evolved  ccm. 
Absorbed  ccm. 

31 
0.81 

32 
0.83 

33 

0.86 

34 

0.88 

35 
0.91 

36 
0.93 

37 
0.96 

38 
0.98 

39 
1.01 

40 
1.03 

Evolved  ccm. 
Absorbed  ccm. 

41 
1.06 

42 
1.08 

43 
1.11 

44 
1.13 

45 
1.16 

46 
1.18 

47 
1.21 

48 
1.23 

49 
1.26 

50 
1.28 

Evolved  ccm. 
Absorbed  ccm. 

51 
1.31 

52 
1.33 

53 
1.36 

54 
1.38 

55 
1.41 

56 
1.43 

57 
1.46 

58 
1.48 

59 
1.51 

60 
1.53 

Evolved  ccm. 
Absorbed  ccm. 

61 
1.56 

62 
1.58 

63 
1.61 

64 
1.63 

65 
1.66 

66 
1.68 

67 
1.71 

68 
1.73 

69 
1.76 

70 
1.78 

Evolved  ccm. 

71 
1  81 

72 
1  83 

73 
1.86 

74 
1.88 

75 
1.91 

76 
1.93 

77 
1.96 

78 
198 

79 
201 

80 
203 

Evolved  ccm. 
Absorbed  ccm. 

81 
2.06 

82 
2.08 

83 
2.11 

84 
2.13 

85 
2.16 

86 
2.18 

87 
2.21 

88 
2.23 

89 
2.26 

90 
2.28 

Evolved  ecm. 
Absorbed  ccm. 

81 
2.31 

92 
2.33 

.  93 
2.36 

94 
2.38 

95 
2.41 

96 
2.43 

97 
2.46 

98 
2.48 

99 
2.51 

100 
2.53 

Calculate  first  to  the  normal  condition,  according  to 
the  formula  given  on  p.  115,  the  quantity  of  nitrogen  read 
off  in  the  graduated  tube,  taking  into  consideration  the 
tension  of  the  aqueous  vapor.  Then  take  from  Dietrich's 
table  the  quantity  of  gas  absorbed  at  the  volume  evolved. 
Add  this  to  the  quantity  of  nitrogen  calculated  to  the 


PLANT-NOURISHING   SUBSTANCES.  123 

normal  state  and  the  equivalent  quantity  of  nitric  acid 
is  obtained  by  muliplying  by  the  factor  0.0048452. 

3.  Special  method  in  the  examination  of  peat. — Peat 
moors,  which  are  to  be  cultivated,  require  special  ex- 
amination. A  determination  of  ash  by  carefully  ignit- 
ing the  substance  dried  at  212°  F.  will  always  have  first 
to  be  executed.  The  content  of  carbonic  acid  in  the  ash 
is  to  be  determined  and  deducted  from  the  per  cent,  of 
ash. 

About  10  grammes  of  the  ash  are  used  for  an  aqueous 
extract,  and  the  calcareous  earth,  magnesia,  potassium, 
sodium,  sulphuric  acid,  and  chlorine  contained  therein 
are  determined.  The  residue  remaining  from  the 
aqueous  extract  is  boiled  with  concentrated  hydrochloric 
acid,  and,  after  separating  the  silica,  alumina,  ferric  oxide, 
calcareous  earth,  magnesia,  potassium,  sodium,  and  phos- 
phoric acid  are  determined.  The  residue  remaining 
thereby  is,  after  boiling  with  sodium  carbonate  solution, 
designated  as  sand. 

II.  Extraction  of  the  soil  with  carbonated  water. — 
Pour  over  1500  grammes  of  air-dry  soil  in  a  flask  6000 
cubic  centimeters  of  water  J  saturated  with  carbonic 
acid,  less  the  quantity  of  water  escaping  from  the  air- 
dry  soil  at  212°  F.  Then  close  the  flask  and  shake. 
The  water  ^  saturated  with  carbonic  acid  is  prepared  by 
completely  saturating,  at  an  ordinary  temperature  and 
with  a  medium  pressure  of  air,  1500  cubic  centimeters 
of  distilled  water  with  carbonic  acid  and  diluting  with 
4500  cubic  centimeters  of  distilled  water.  The  soil 
remains  in  contact  with  the  water  for  three  days,  the 
flask  being  frequently  rolled  upon  a  soft  support.  The 
soil  is  then  allowed  to  settle  and  5000  cubic  centimeters 


124  THE   EXAMINATION   OF   SOILS. 

of  the  supernatant  clear  fluid  are  siphoned  off  in  two 
separate  portions,  one  of  1000  and  the  other  of  4000  cubic 
centimeters.  The  two  fluids  are  then  allowed  to  stand 
quietly  in  hermetically  closed  flasks  for  twenty-four 
hours,  when  they  are  filtered  off  clear  without  stirring 
up  the  sediment.  During  this  operation  the  filtering 
funnel  should  be  kept  covered. 

The  1000  cubic  centimeters,  which  correspond  to  250 
grammes  of  soil  dried  at  212°  F.,  are  now  gradually 
evaporated  to  dryness  in  a  small  weighed  platinum  dish 
upon  the  water-bath.  The  residue  is  dried  in  the  air- 
bath  at  257°  F.,  and  quickly  weighed  after  cooling  in 
the  desiccator.  By  this  means  the  sum  total  of  the  sub- 
stances dissolved  in  the  carbonated  water  is  found.  The 
mass  is  then  moderately  ignited,  several  times  moistened 
with  ammonium  carbonate,  again  ignited,  cooled  in  the 
desiccator,  and  once  more  weighed.  In  this  manner  the 
sum  total  of  the  refractory  inorganic  salts  is  obtained, 
and  their  content  of  carbonic  acid  can  best  be  de- 
termined by  the  method  given  on  p.  64.  The  determina- 
tion of  the  carbonic  acid  being  finished,  the  fluid  in  the 
flask  may  further  be  used  for  the  qualitative  determina- 
tion of  the  presence  of  the  various  constituents. 

The  greater  portion  of  the  carbonated  aqueous  ex- 
tract (4000  cubic  centimeters  corresponding  to  1000 
grammes  of  the  soil  dried  at  212°  F.)  is  also  filtered. 
In  case  the  filtrate  is  not  entirely  clear,  E.  Wolff  pro- 
poses to  evaporate  the  fluid  to  400  cubic  centimeters, 
slightly  over-saturate  it,  while  still  hot,  with  hydro- 
chloric acid,  and  to  filter  off  the  small  quantity  of  in- 
soluble clay.  To  destroy  the  humus  substances,  as  well 
as  to  oxidize  the  iron,  the  fluid  is  compounded  with  a 


PLANT-NOURISHING   SUBSTANCES.  125 

few  drops  of  nitric  acid  and  evaporated  to  pulverulent 
dryness  by  heating  it  in  a  porcelain  crucible,  several 
times  moistening  the  substance  with  water  when  it  be- 
comes dry,  and  rubbing  it  to  a  powder  with  a  glass 
pestle.  The  mass  is  then  moistened  with  hydrochloric 
acid,  and,  after  adding  boiling  water,  the  fluid  is  filtered 
to  separate  silica.  In  the  filtrate,  alumina,  ferric  oxide, 
phosphoric  acid,  calcareous  earth,  magnesia,  sulphuric 
acid,  potassium,  and  sodium  are  determined. 

The  fluid  is  now  heated  to  boiling  and  compounded 
with  ammonia  slightly  in  excess.  A  weighable  precipi- 
tate of  ferric  oxide  will  only  be  formed  with  acid  humus 
soils.  If,  however,  the  precipitate  is  too  small  to  be 
weighed,  redissolve  it  by  adding  a  few  drops  of  hydro- 
chloric acid,  compound  the  boiling-hot  solution  with  a 
few  drops  of  very  dilute  ferric  chloride  solution  and 
again  precipitate  with  ammonia  slightly  in  excess.  The 
precipitate  contains  the  entire  quantity  of  phosphoric 
acid  dissolved  in  the  carbonated  water  as  ferric  phos- 
phate (FePOJ.  Filter  the  precipitate  off,  wash  it  with 
hot  water  until  a  drop  running  off  from  the  funnel  is  no 
longer  made  turbid  by  silver  nitrate,  and  then  detach  it 
as  much  as  possible  from  the  filter  with  a  feather.  The 
particles  of  the  precipitate  still  adhering  to  the  filter  are 
dissolved  with  hot  dilute  nitric  acid  by  allowing  the 
latter  to  fall  drop  by  drop  upon  the  filter  and  placing 
the  beaker  containing  the  detached  precipitate  under- 
neath the  filter.  Wash  the  filter  with  hot  water.  Then 
heat  the  fluid  in  the  beaker  and  add  nitric  acid  until  the 
precipitate  is  dissolved.  The  solution  is  evaporated  to 
a  small  quantity  in  a  porcelain  dish  and  rinsed  with  as 
little  water  as  possible  into  the  beaker. 


126  THE   EXAMINATION   OF   SOILS. 

Precipitation  of  the  phosphoric  acid  with  ammonium 
molybdate  and  weighing  as  magnesium  pyrophosphate. — 
The  ammonium  molybdate  solution  required  for  the  pre- 
cipitation of  the  phosphoric  acid  is  prepared  as  follows  : 
Dissolve  40  grammes  of  ammonium  molybdate  in  80 
cubic  centimeters  of  concentrated  ammonia  and  320 
cubic  centimeters  of  distilled  water  and  slowly  pour  the 
fluid,  with  constant  stirring,  into  a  mixture  of  480  cubic 
centimeters  of  nitric  acid  (1.18  specific  gravity),  and  120 
cubic  centimeters  of  water. 

Of  the  solution  thus  prepared,  add  an  abundant 
quantity  to  the  fluid  to  be  examined,  and  let  the  mixture 
stand  for  twelve  hours  at  104°  F.  During  this  time  the 
phosphoric  acid  separates  as  ammonium  phospho- 
molybdate  in  the  form  of  a  yellow  granular  crystalline 
precipitate.  Now  siphon  off  a  small  portion  of  the 
supernatant  clear  fluid,  and  test  it  as  to  whether  a  pre- 
cipitate is  again  formed  after  once  more  adding  am- 
monium molybdate  solution  and  standing  for  some  time. 
If  such  is  the  case,  the  test  sample  is  again  added  to  the 
whole,  and,  after  adding  fresh  ammonium  molybdate 
solution,  it  is  again  allowed  to  stand  for  twelve  hours  at 
104°  F. 

The  supernatant  fluid  is  then  poured  off  through  a 
small  filter,  and  the  precipitate  in  the  beaker  repeatedly 
washed,  by  decanting,  with  a  mixture  of  100  parts  of 
ammonium  molybdate  solution,  20  parts  of  nitric  acid 
of  1.2  specific  gravity,  and  80  parts  of  water.  To  be 
sure  that  all  the  iron  is  in  the  filtrate,  the  wash-water 
running  off  from  the  filter  towards  the  end  of  the  opera- 
tion should  not  yield  a  precipitate  on  being  compounded 
with  ammonia.  Now  place  the  beaker  containing  the 


PLANT-NOURISHING   SUBSTANCES.  127 

washed  precipitate  under  the  funnel,  dissolve  any  particles 
of  the  precipitate  adhering  to  the  filter  in  a  few  drops 
of  concentrated  ammonia,  and  wash  the  filter  with  a 
mixture  of  one  volume  ammonia  and  three  volumes 
water.  If  the  precipitate  in  the  beaker  does  not  dissolve 
entirely  clear,  the  fluid  must  be  again  poured  through 
the  filter  before  washing  the  latter.  To  the  clear  filtrate 
add,  drop  by  drop,  hydrochloric  acid  until  the  yellow 
precipitate  formed  thereby  only  disappears  after  repeated 
shaking.  Then  precipitate  the  phosphoric  acid  as  am- 
monium magnesium  phosphate  with  magnesia  mixture. 
The  magnesia  mixture  is  prepared  as  follows  :  Dissolve 
1  part  of  crystallized  magnesium  sulphate  and  2  parts  of 
ammonium  chloride  in  8  parts  of  water,  and  4  parts  of 
ammonia.  The  precipitate  is- washed,  as  given  on  p.  71, 
with  ammoniacal  water,  dried,  ignited,  and  weighed  as 
magnesium  pyrophosphate.  To  calculate  from  this  the 
phosphoric  acid,  multiply  the  weighed  quantity  by  the 
factor  0.64. 

Determination  of  the  phosphoric  acid  as  ammonium 
phospho-molybdate,  according  to  R.  Finkener. — By  this 
method  the  precipitation  of  the  phosphoric  acid  with 
magnesia  mixture  is  avoided,  and  it  has  the  further  ad- 
vantage that  even  in  the  presence  of  very  small  quanti- 
ties of  phosphoric  acid,  a  comparatively  large  weight  is 
brought  upon  the  balance. 

When  the  phosphoric  acid  has  been  precipitated,  after 
adding  25  per  cent,  ammonium  nitrate,  with  ammonium 
molybdate  in  the  manner  described  on  p.  120,  the  precip- 
itate is  brought  upon  a  small  filter  and  washed  with  a 
solution  of  ammonium  nitrate,  which  contains  20  per 
cent,  of  the  salt  and  is  previously  mixed  with  -fa  its 
volume  of  nitric  acid.  Washing  is  finished  when  the 


128 


THE   EXAMINATION   OF   SOILS. 


solution  running  off  is  no  longer  immediately  colored  by 
yellow  prussiate  of  potash. 

When  the  greater  portion  of  the  ammonium  nitrate 
has  been  removed  by  washing  with  some  water,  the  pre- 
cipitate is  injected  by  means  of  a  wash-bottle  from  the 
filter  into  a  weighed  porcelain  crucible.  What  adheres 
to  the  paper  is  detached  with  heated  liquid  ammonia, 
and  after  concentrating  this  solution  by  evaporating  and 
oversatu rating  it  with  nitric  acid,  it  is  also  brought  into 
the  crucible.  After  the  fluid  is  first  evaporated  upon 


the  water-bath,  the  crucible  is  placed  by  means  of  a 
triangle  upon  Finkener's  drying  stand  (Fig.  18),  in 
which  the  flame  is  cooled  off  by  three  different  wire 
screens  placed  one  above  the  other.  Only  a  moderate 


PLANT-NOURISHING   SUBSTANCES.  129 

heat  is  required  for  the  expulsion  of  the  ammonium 
nitrate.  The  operation  is  finished  when  a  watch-crystal 
placed  over  the  crucible  is  not  tarnished.  The  ammo- 
nium phospho-molybdate  remaining  in  the  crucible  con- 
tains for  1  part  of  phosphoric  acid  (P2OS)  24  parts  of 
molybdic  acid  (M0O3).  It  is  placed,  while  hot,  in  the  desic- 
cator filled  with  sulphuric  acid  and,  when  cold,  quickly 
weighed  since  it  is  hygroscopic.  To  calculate  the  salt 
to  the  equivalent  quantity  of  phosphoric  acid  (P3Ot)  mul- 
tiply the  weighed  quantity  by  the  factor  0.03794. 

Further  treatment  of  the  soil  extract  prepared  with  car- 
bonated ivater. — The  filtrate  from  the  precipitate  with 
ammonia  (p.  125)  is  heated  to  boiling  and  the  calcareous 
earth  precipitated  with  ammonium  oxalate  in  the  manner 
given  on  p.  68  et  seq. 

After  the  calcium  oxalate  has  been  filtered  off,  evapo- 
rate the  fluid  to  about  10  cubic  centimeters,  compound 
it  with  a  few  drops  of  hydrochloric  acid  until  it  shows 
an  acid  reaction,  and  precipitate  the  sulphuric  acid  with 
barium  chloride  solution  without,  however,  adding  too 
large  an  excess  of  it.  The  precipitate,  consisting  of 
barium  sulphate,  is  treated  in  the  same  manner  as 
described  on  p.  109  for  the  determination  of  sulphuric 
acid  in  the  aqueous  extract. 

In  the  filtrate  the  excess  of  barium  sulphate  is  pre- 
cipitated by  a  few  drops  of  sulphuric  acid,  the  precipi- 
tate filtered  off  and  the  fluid  after  being  neutralized  with 
ammonia  is  evaporated,  with  constant  stirring,  to  dry- 
ness  in  a  platinum  dish.  The  ammoniacal  salts  are 
then  expelled  by  igniting,  the  residue  is  taken  up  with 
some  hydrochloric  acid  and  water,  and  filtered  in  case 
some  more  barium  sulphate  has  separated.  From  the 
9 


130  THE   EXAMINATION   OF   SOILS. 

very  concentrated  solution,  the  magnesia  is  precipitated 
by  ammonium  carbonate  (compare  p.  104  et  seq.").  Weigh 
the  alkalies  as  sulphates  and  separate  the  potassium  by 
precipitating  with  platinum  chloride  and  taking  up  the 
precipitate  with  the  mixture  of  hydrochloric  acid,  alco- 
hol and  ether,  in  the  manner  described  on  p.  108. 

III.  Extraction  of  the  soil  with  cold  concentrated  hy- 
drochloric acid. — Pour  over  200  grammes  of  air-dry 
soil  in  a  cylinder,  which  can  be  closed  with  a  glass 
stopper,  400  grammes  of  pure  concentrated  hydrochloric 
acid  and  allow  the  latter  to  act  upon  the  substance  at 
the  ordinary  temperature  of  a  room,  for  forty-eight  hours, 
shaking  the  cylinder  frequently.     The  hydrochloric  acid 
is  then  much  diluted,  poured  off  through  a  filter,  and 
the  soil  washed  by  repeatedly  decanting  it  with  hot 
water  until  a  drop  running  off  from  the  funnel  shows 
no  reaction  with  silver  nitrate. 

The  separation  of  the  dissolved  substances  is  effected 
in  the  same  manner  as  with  soil  treated  with  boiling 
concentrated  hydrochloric  acid. 

IV.  Extraction  of  the  soil  with  boiling  concentrated 
hydrochloric  acid. — Only  in  a  few  cases  will  it  be  pos- 
sible to  simultaneously  prepare  the  four  extracts  men- 
tioned on  p.  102,  they  requiring  much  labor  and  time. 
Hence,  as  a  rule,  the  experimenter  will  have  to  be  satis- 
fied with  one  extract,  and,  in  such  a  case,  it  is  best  to 
chose  that  with  boiling  concentrated  hydrochloric  acid, 
which,  as  previously  mentioned,  contains  the  sum-total 
of  all  the  plant-nourishing  substances   available   at   the 
present  and  becoming  active  in  the  future. 

Of  sand  soils  weigh  out  100  grammes,  and  of  clay 
soils  50  grammes  of  the  air-dry  fine  soil.  Bring  the 


PLANT-NOURISHING   SUBSTANCES. 


131 


Fig.  19. 


weighed  out  quantity  into  an  Erlenmeyer  boiling  flask 
and  pour  over  it,  in  the  first  ease,  200,  and  in  the  latter, 
100  cubic  centimeters  of  pure  concentrated  hydrochloric 
acid  of  1.15  specific  gravity.  Put  the  boiling  flask 
upon  a  sand-bath  (Fig.  19),  and  place  upon  it  a  small 
funnel,  c,  with  a  short  tube,  using,  however,  the  pre- 
caution of  inserting  between  the  neck  .of  the  flask  and 
the  funnel  a  small  piece  of  a  glass  rod,  6,  bent  at  an 
angle  of  45°,  so  that  in  boiling  the 
vapors  can  escape  unrestrained,  and 
the  scattering  of  the  fluid  through  the 
funnel  tube  is  prevented. 

The  soil  is  boiled  with  the  acid 
exactly  one  hour.  Then  add  a  large 
excess  of  distilled  water,  stir  with  a 
glass  rod,  and  allow  the  soil  to  settle. 
When  the  supernatant  fluid  is  clear, 
pour  it  off  through  a  filter  and  wash 
the  soil  in  the  boiling  flask  by  decant- 
ing with  hot  water  until  a  drop  run- 
ning off  from  the  filter  shows  no 
turbidity  with  silver  nitrate. 

The  clear  filtrate  is  compounded 
with  some  nitric  acid,  and,  to  separate 
the  dissolved  silica,  is  then  brought  to  dusty  dryness  in 
a  porcelain  dish  upon  the  water-bath.  The  separation 
of  the  silica  must  be  very  carefully  done,  as  otherwise 
it  will  erroneously  affect  the  determination  of  phosphoric 
acid. 

The  filtrate  from  the  silica  is  compounded  hot  with 
ammonia,  the  ferric  oxide  and  alumina  being  thereby 
precipitated.  Then  add  a  few  drops  of  acetic  acid 


132  THE   EXAMINATION   OF  SOILS. 

until  the  fluid  shows  a  slight  acid  reaction  and  boil 
again.  The  precipitate  which,  as  a  rule,  is  considerable, 
is  brought  upon  two  large  rapidly  filtering  filters, 
thoroughly  washed  with  hot  water,  and  then  detached  as 
much  as  possible  from  the  filters  with  the  aid  of  a 
feather.  The  particles  adhering  to  the  filters,  as  well 
as  the  detached  precipitate,  are  dissolved  in  hot  dilute 
nitric  acid.  Bring  the  solution  into  a  flask  of  500  cubic 
centimeters  capacity,  and  take  100  cubic  centimeters  of 
it  by  means  of  a  pipette  for  the  determination  of  iron 
and  alumina.  The  remaining  400  cubic  centimeters  are 
evaporated  to  a  small  quantity  and  used  for  the  de- 
termination of  phosphoric  acid  according  to  the  method 
described  on  p.  127.  In  the  100  cubic  centimeters,  pre- 
cipitate the  ferric  oxide  and  alumina  with  ammonia, 
weigh  the  ignited  precipitate,  dissolve  it  in  hydrochloric 
acid  or  potassium  sulphate,  and  determine  the  iron  by 
titration  with  potassium  permanganate  solution  in  the 
manner  described  on  p.  87  et  seq. 

The  total  filtrate  of  the  principal  precipitate  is  com- 
pounded with  ammonium  sulphide,  whereby  the  man- 
ganese is  precipitated  as  manganous  sulphide.  The 
precipitate  is  filtered,  washed  with  water  containing  am- 
monium sulphide,  and,  after  drying,  incinerated,  together 
with  the  filter,  in  a  weighed  crucible.  Now  add  some 
flowers  of  sulphur,  heat  the  crucible  in  a  current  of 
hydrogen  and  let  it  also  cool  in  it.  The  green  residue 
in  the  crucible  consists  of  manganous  sulphide  (M,,S), 
which,  after  cooling  in  the  desiccator,  is  weighed.  The 
equivalent  quantity  of  manganous  oxide  is  obtained  by 
multiplying  the  mangauous  sulphide  by  the  factor 
0.877.  ' 


PLANT-NOURISHING   SUBSTANCES.  133 

The  filtrate  from  the  precipitate  with  ammonium  sul- 
phide is  over-saturated  with  hydrochloric  acid  and  boiled 
until  the,  at  first,  milky  sulphur  separated,  balls  together 
on  the  bottom,  and  the  supernatant  fluid  is  clear.  The 
sulphur  is  filtered  off,  the  filter  washed,  and  the  calcare- 
ous earth,  magnesia,  and  alkalies  are  determined  in  the 
filtrate  in  the  manner  given  on  p.  104  et  seq. 

If  the  quantity  of  silica  separated  in  soluble  form  in 
the  extract  with  hydrochloric  acid  is  to  be  determined, 
the  silica  which  has  been  dissolved  in  the  hydrochloric 
acid  and  separated  in  an  insoluble  form  in  evaporating  the 
latter,  must  be  weighed  as  well  as  that  remaining  in  solu- 
ble modification  in  the  soil.  For  this  purpose  repeatedly 
boil  the  soil-residue  from  the  extract  with  hydrochloric 
acid  with  concentrated  sodium  carbonate  solution  to 
which  some  soda  lye  has  been  added.  Then  filter  off  the 
soil  and  over-saturate  the  filtrate  with  hydrochloric  acid 
by  covering  it  with  a  watch  crystal  and  slowly  adding 
the  acid  drop  by  drop.  The  fluid  is  then  evoporated  to 
dusty  dryness,  the  residue  taken  up  with  hydrochloric 
acid,  diluted  with  distilled  water  and  the  silica,  separated 
in  an  insoluble  form,  ignited  and  weighed  in  the  manner 
described  on  p.  97  et  seq. 

B.  Determination  of  some  important  substances  for  the 
nourishment  of  plants,  which  can  either  not,  or  only 
partially,  be  determined  in  the  soil-extracts.  1.  Determina- 
tion of  the  total  nitrogen  in  the  soil.  a.  KjeldahFs 
method. — This  process  was  devised  by  J.  Kjeldahl,  of 
Copenhagen.  It  is  based  upon  the  theory  that  the  sub- 
stance, which  is  to  be  used  dry,  is  so  altered  by  boiling 
for  some  time  with  an  abundant  quantity  of  concen- 
trated sulphuric  acid,  that  by  the  succeeding  oxidation 


134  THE    EXAMINATION    OF    SOILS. 

with  dry  pulverulent  potassium  permanganate,  all  the 
nitrogen  is  converted  into  ammonia.  A  modified  pro- 
cess adapted  for  the  investigation  of  soils  is  as  fol- 
lows : — 

The  substance  dried  at  212°  F.  is  poured  from  a  long 
thin  weighing  tube  into  a  boiling  flask  of  100  cubic 
centimeters  capacity,  care  being  had  that  no  substance 
remains  adhering  in  the  neck.  With  humus  and  peat 
soil  0.5  to  1  gramme  of  the  finely  pulverized  soil  is  used, 
and  with  humus  sand  soils  and  fat  and  clammy  soils  2 
to  5  grammes.  Then  add  20  cubic  centimeters  of  a 
mixture  of  16  volumes  of  pure  concentrated  sulphuric 
acid,  4  of  pure  fuming  sulphuric  acid,  and  2  grammes 
of  anhydrous  phosphoric  acid,  place  the  boiling  flask  in 
an  oblique  position  upon  the  sand-bath  and  boil  the 
fluid  until  it  has  acquired  a  wine-yellow  color.  Then 
remove  the  flame,  and,  after  cooling  somewhat,  add  to 
the  solution,  while  still  hot,  an  excess  of  dry  pulverulent 
potassium  permanganate  in  small  portions  until  the 
solution  has  acquired  a  blue-green  color.  After  cooling, 
the  solution  is  brought  into  a  boiling  flask  holding  one 
liter  (Fig.  20),  and  diluted  with  distilled  water  to  200 
cubic  centimeters.  The  boiling  flask  is  connected  by 
means  of  a  rubber  cork  with  an  obliquely  ascending 
glass  tube  expanding  to  a  bulb,  which  enters  a  glass 
receiver.  From  the  other  end  of  the  receiver  a  tube 
leads  into  an  Erlenmeyer  boiling  flask  which  contains 
some  pure  dilute  hydrochloric  acid  in  which,  however, 
the  tube  need  not  to  dip.  Now  open  the  rubber  cork,  add 
to  the  fluid  80  cubic  centimeters  of  soda  lye  which  con- 
tains 50  grammes  of  caustic  soda,  and  quickly  replace 
the  cork  upon  the  boiling  flask.  Now  distil  the  fluid 


PLANT-NOURISHING   SUBSTANCES. 


135 


for  half  an  hour,  during  which  time  the  ammonia  is 
completely  expelled  and  absorbed  by  the  hydrochloric 
acid  in  the  receiver.  The  hydrochloric  acid  is  evapo- 
rated to  dryness,  rinsed  with  10  cubic  centimeters  of 


Fi 


distilled  water  into  the  developing  vessel  of  the  Knop- 
Wagner  azotometer  and  the  nitrogen  determined 
volumetrically  by  decomposing  the  sal  ammoniac  with 
bromine  lye  (compare  p.  118). 

b.    Determination  of  the  nitrogen  by  combustion  with 
soda  lime. — For  this  determination  use  a  tube  of  hard 

Fig.  21. 


5ifjt.ni. 


glass  of  the  form  shown  in  Fig.  21.     Before  drawing 
the  tube  out  it  is  thoroughly  cleansed,  and,  after  heating, 


136  THE   EXAMINATION   OF   SOILS. 

dried  by  sucking  out  the  air.  Now  first  slip  into  the 
tube  a  loosely  fitting  plug  of  asbestos,  previously  ignited, 
and  then  a  layer  of  3  to  4  cubic  centimeters  of  soda 
lime  free  from  nitric  acid  previously  moderately  heated 
in  a  porcelain  dish,  and  which,  for  use,  should  have  a 
temperature  of  104°  to  122°  F.  Now  weigh  out  1  to 
10  grammes  of  fine  soil  finely  pulverized  and  dried  at 
212°  F.,  and  mix  it  in  a  porcelain  mortar  with  some 
warm,  finely  pulverized  soda  lime  and  about  J  gramme 
of  pure  cane  sugar.  Introduce  the  mixture,  while  warm, 
into  the  combustion  tube,  forcible  pressure  being  care- 
fully avoided.  The  mixture  is  followed  by  a  layer  of 
soda  lime  used  to  rinse  the  mortar.  Then  add  enough 
granulated  soda  lime  to  fill  the  tube  to  about  4  centi- 
meters of  the  open  end  and  place  another  plug  of  ignited 
asbestos  at  the  end.  In  the  tube  is  inserted,  by  means 
of  a  rubber  cork,  the  end  of  a  Will-Varrentrapp  appa- 
ratus, which  is  previously  filled,  by  means  of  a  pipette, 
to  one-quarter  of  its  volume  with  pure  distilled  water, 
and  1  cubic  centimeter  of  pure  concentrated  hydrochloric 
acid,  as  shown  in  Fig.  21.  The  hydrochloric  acid  used 
must  first  be  tested  as  to  its  purity  ;  and  should  leave  no 
residue  after  evaporating  with  platinum  chloride  and 
taking  up  the  mass  with  alcohol. 

Before  placing  the  tube  in  the  combustion  furnace,  a 
free  passage  is  formed  for  the  evolved  gases  by  a  few 
gentle  taps.  The  tube  is  then  gradually  heated  com- 
mencing at  the  fore  part  nearest  the  cork  and  progress- 
ing slowly  towards  the  tail.  Care  must  be  taken  to 
keep  the  fore  part  of  the  tube  at  a  moderate  red  heat 
throughout  the  process.  The  addition  of  sugar  is  claimed 
to  promote  the  conversion  of  the  nitrogen  into  ammonia. 


PLANT-NOURISHING   SUBSTANCES.  137 

Combustion  is  finished  when  no  more  black  carbonace- 
ous particles  are  perceptible  in  the  substance.  Now 
break  off  the  point  of  the  ascending  tube  and  at  the  same 
time  put  out  the  gas.  Then  by  means  of  an  aspirator 
connected  by  rubber  tubing  with  the  end  of  the  "Will- 
A'arrentrapp  apparatus  draw  a  slow  current  of  air 
through  the  apparatus.  Now  pour  the  fluid  from  the 
Will-Varrentrapp  apparatus  into  a  porcelain  dish,  rinse 
out  with  water,  and  evaporate  nearly  to  dryness.  By 
now  taking  the  residue  up  with  some  water,  the  greater 
portion  of  tarry  substances  formed  by  combustion  re- 
mains in  the  dish.  The  fluid  containing  the  sal  ammo- 
niac is  evaporated  nearly  to  dryness  in  a  small  dish 
upon  the  water-bath,  and  the  nitrogen  determined  either 
volumetrically  in  the  Knop- Wagner  azotometer  (see  p. 
118  etseq)  or  weighed  as  ammonio-platinum  (see  p.  117). 
2.  Determination  of  the  ammonia  contained  in  the 
soil. — As  a  rule  soils  contain  but  small  quantities  of 
ammoniacal  gas  and  arnmoniacal  salts,  they  being  gener- 
ally rapidly  oxidized  to  nitric  acid.  To  determine  them, 
it  is  best  to  fill  the  soil  taken  from  the  field  in  its  natu- 
ral moist  condition  into  a  wide-necked  glass  flask,  close 
the  latter  hermetically  and  use  the  soil  for  analysis  as 
soon  as  possible  after  being  taken  from  the  field.  The 
methods  based  upon  distilling  the  soil  compounded  with 
water  with  soda  lye  or  manganic  oxide  and  catching  the 
escaping  ammonia  in  a  receiver  do  not  yield  accurate 
results,  since  after  the  expulsion  of  the  ammonia  already 
formed,  the  nitrogenous  organic  substances  are  also  at- 
tacked and  constantly  yield  small  quantities  of  ammonia. 
The  following  method  can,  however,  be  recommended  : 


138  THE   EXAMINATION   OF  SOILS. 

Schloesing's  modified  method  for  the  accurate  determi- 
nation of  the  ammonia  in  the  soil. — Introduce  100  grammes 
of  the  soil  into  a  liter  flask,  and  at  the  same  time  deter- 
mine, from  the  loss,  the  water  which  escapes  at  212°  F. 
from  about  20  grammes  of  the  sample  used,  so  that  later 
on  the  content  of  ammonia  can  be  calculated  to  sub- 
stance dried  at  21 2°  F. 

Pour  over  the  soil  in  the  flask,  100  cubic  centimeters 
of  distilled  water,  and  add  from  a  burette  concentrated 
hydrochloric  acid,  until  any  carbonic  acid  present  is  com- 
pletely expelled,  and  the  fluid  contains  an  excess  of  hy- 
drochloric acid.  To  the  measured  quantity  of  hydro- 
chloric acid,  previously  tested  as  to  its  purity  by  evapo- 
rating with  platinum  chloride,  add  sufficient  distilled 
water  to  make  exactly  400  cubic  centimeters  of  fluid. 
Then  close  the  liter  flask  with  a  rubber  cork,  shake  vig- 
orously and  allow  the  soil  to  settle,  for  which  6  to  12 
hours  are  required.  The  supernatant  clear  fluid  is  then 
quickly  poured  through  a  dry,  folded  filter,  and  200  cubic 
centimeters  of  the  filtrate,  corresponding  to  5  grammes 
of  the  soil  used,  are  taken  out  with  a  pipette.  Evapo- 
rate these  200  cubic  centimeters  to  10  cubic  centimeters 
in  a  room  free  from  ammonia  and  rinse  them  into  a  half 
liter  flask,  so  that  the  fluid  amounts  to  about  100  cubic 
centimeters.  Now  add  concentrated  soda  lye  until  it  is 
present  in  excess,  introduce  some  granulated  zinc  into 
the  flask  and  distil  off  one-half  of  the  fluid  through  a 
receiver  into  an  Erlenmeyer  boiling  flask,  which  con- 
tains some  dilute  hydrochloric  acid  for  the  reception  of 
the  ammoniacal  gas.  AVhen  distillation  is  finished,  the 
distillate  is  evaporated  nearly  to  dryness  and  the  nitro- 


INJURIOUS   TO   THE   GROWTH   OF   PLANTS.        139 

gen  volumetrically  determined   in   the    Kuop- Wagner 
azotometer. 

If,  now,  the  cubic  centimeters  of  nitrogen  calculated 
to  the  normal  condition  are  multiplied  by  the  factor 
0.001525,  the  content  in  grammes  of  ammoniacal  gas 
(NH3)  in  50  grammes  of  the  soil  used  is  obtained. 


VIII. 

DETERMINATION    OF    THE    SUBSTANCES    IN    THE 
SOIL  INJURIOUS  TO  THE  GROWTH  OF  PLANTS. 

THE  presence  of  certain  substances  in  the  soil  may 
essentially  influence  the  growth  of  plants,  and  in  many 
cases  render  it  even  entirely  impossible.  Among  these 
so-called  poisons  to  cultivated  plants  may  be  included : 
Humic  acids  showing  an  acid  reaction,  too  large  quantities 
of  common  salt,  free  sulphuric  acid,  ferrous  sulphate, 
and  iron  bisulphide.  In  many  cases  the  establishment 
of  the  presence  of  these  substances  suffices  without  the 
necessity  of  their  quantitative  determination.  Their 
presence  can  be  partially  shown  in  preparing  the  aqueous 
extract  for  the  determination  of  the  plant-nourishing 
substances. 

1.  Proof  of  the  presence  of  free  humic  acids  in  the 
soil. — If  the  aqueous  extract  of  a  humus  soil  shows  a 
distinct  acid  reaction  towards  litmus-paper ;  and  when 
the  presence  of  sulphuric  acid  cannot  be  established  by 
barium  chloride,  the  acid  will  have  to  be  traced  back  to 
humus  substances.  Soils  showing  this  phenomenon 
generally  also  suffer  from  too  much  moisture,  and  the 


140  THE   EXAMINATION   OF   SOILS. 

field  will  have  to  be  sufficiently  drained  by  ditches  or 
raised  by  carting  sand  upon  it.  Liming  and  marling 
will  also  be  of  advantage  for  fixing  the  humic  acids. 

2.  Determination  of  the  content  of  common  salt  in  the 
soil. — Voelker's   and    Grandeau's    investigations   have 
shown  that  a  soil  becomes  unproductive  when  its  con- 
tent of  common  salt  exceeds  0.1  per  cent.     In  discussing 
the  aqueous  extract  for  the  estimation  of  the   plant- 
nourishing  substances,  the  determinations  of  the  content 
of  chlorine  and  sodium  have  been  considered.     In  most 
cases  the  quantity  of  chlorine  found  can   be  directly 
calculated  to  sodium. 

3.  Determination  oftheferrom  sulphate,  free  sulphuric 
add,  and  iron  disulphide.     The  occurrence  of  ferrous 
sulphate  (green  vitriol)  or  free  sulphuric  acid  is  dependent 
on   the  presence  of  iron  disulphide  in  the  soil.     Iron 
pyrites  which,  according  to  Fleischer's  investigations, 
are  occasionally  found  in  the  soil,  yield  by  their  oxida- 
tion through  oxygen  free  sulphuric  acid  and  ferrous  sul- 
phate —  FeS2  +  7  O  =  SO3  +  FeSO4.     These  combina- 
tions will  always  be  formed  when  not  sufficient  bases, 
especially  lime,  are  present  for  their  saturation.     The 
presence  of  iron   disulphide  in  the  sands  under  peat 
moors  has  several  times  caused  complete  failures  in  the 
establishment  of  the  Rimpau  moor-dam  cultivation,  in 
which  such  sand  was  brought  upon  the  moor.     Hence, 
it   is   of  importance   to   examine   the   moor  soil  to  be 
cultivated,  as  well  as  the  sand  to  be  used,  in  regard  to 
these  injurious  substances. 

In  the  Prussian  moor  experimental  station  at  Bremen, 
the  following  methods  are  used  : — 

Of  the  moor  or  sand  to  be  examined,  an  aqueous 


INJURIOUS   TO   THE   GROWTH   OF   PLANTS.        141 

extract  is  prepared  and  tested  for  the  presence  of  ferrous 
oxide  by  adding  solution  of  red  prussiate  of  potash. 
The  presence  of  ferrous  oxide  is  immediately  recognized 
by  the  blue  coloration  of  the  fluid.  Any  acid  reaction 
is  determined  by  litmus  paper. 

In  the  aqueous  extract  of  100  grammes  of  soil,  potas- 
sium, sodium,  calcareous  earth,  magnesia,  ferrous  or 
ferric  oxide,  chlorine,  and  sulphuric  acid  are  determined, 
and  the  bases  calculated  to  the  acids  present.  The 
excess  of  sulphuric  acid  can  be  designated  as  free. 

a.  Determination  of  the  content  of  sulphur  in  the  soil  by 
ignition. — Ignite  20  grammes  of  the  fine  soil  extracted 
with  water  and  dried  in  a  Bohemian  glass  tube  in  a  cur- 
rent of  air,  whereby  any  iron  pyrites  present  are  decom- 
posed and  the  sulphur  is  transformed  into  sulphuric  and 
sulphurous  acids. 

First  slip  a  plug  of  glass-wool  into  the  tube  (Fig.  22), 
then  pour  the  substance  loosely  upon  it  and  insert  another 
plug  of  glass-wool.  The  tail  end  of  the  tube  communi- 
cates with  a  vessel  filled  with  water  which  serves  for 
controlling  the  current  of  air  to  be  used  in  the  combus- 
tion. The  fore  part  of  the  tube  is  drawn  out,  bent  at 
a  right  angle  downward  and  connected  with  an  absorb- 
ing vessel  filled  with  potash  lye  free  from  sulphuric  acid. 
By  means  of  the  aspirator  attached  to  the  absorbing 
vessel  a  current  of  air  can  be  constantly  conducted 
through  the  combustion  tube.  Between  the  absorbing 
vessel  and  the  aspirator  is  first  a  funnel  tube  with  glass 
beads  moistened  with  potash  lye,  and  next  a  bulb  tube 
containing  some  neutral  litmus  solution,  which  during 
the  operation  should  not  change  its  color.  The  tube  is 
placed  in  a  combustion  furnace  and  gradually  heated  to 


142 


THE   EXAMINATION   OF   SOILS. 


a  red  heat,  commencing  at  the  tail  and  progressing 
slowly  towards  the  fore  part.  When  the  tube  is  ignited 
throughout  its  whole  length,  the  products  of  distillation 
condensed  in  the  drawn  out  portion  of  the  tube  are 


finally,  by  means  of  a  flame,  forced  down  as  far  as  pos- 
sible, so  that  when  the  operation  is  finished  they  can  be 
readily  rinsed  out  writh  the  wash-bottle.  The  potash  lye 
is  oversaturated  with  hydrochloric  acid,  compounded 
with  bromine,  to  convert  the  sulphurous  acid  into  sul- 
phuric acid,  and  the  bromine  removed  by  boiling.  Now 
precipitate  the  sulphuric  acid  writh  barium  chloride,  ob- 
serving the  precautionary  measures  given  on  p.  110,  since 
the  heavy  precipitate  in  the  concentrated  common  salt 
solution  generally  carries  alkali  down  with  it.  With 
peats  it  is  advisable  to  ignite  the  substance  in  a  current 
of  oxygen. 

By  igniting  the  soil  in  a  tube  the  entire  quantity  of 
sulphuric  acid  contained  in  it  is  not  obtained,  but  in  the 


INJURIOUS   TO   THE   GROWTH   OF   PLANTS.        143 

investigations  of  the  moor  experimental  station  at 
Bremen  this  method  has  proved  itself  as  sufficiently 
accurate. 

From  the  above-mentioned  methods,  Fleischer  calcu- 
lates the  sulphuric  acid  present  in  a  form  injurious  to 
plants  as  follows  : — 

1.  Present  as  free  acid  (the  residue  of  sulphuric  acid 
which  remains  after  calculating  the  acid  to  the  bases  of 
the  aqueous  extract). 

2.  Sulphuric  acid  contained  in  ferrous  sulphate  (calcu- 
lated from  the  content  of  ferrous  oxide  in  the  aqueous 
extract). 

3.  Sulphuric  acid  which  may  be  formed  from  iron 
disulphide  (obtained  by  igniting  the  soil  extracted  with 
water). 

6.  Determination  of  the  content  of  sulphur  in  the  soil  by 
disintegration  with  bromine. — Fuse  5  to  10  grammes  of 
the  finely  powdered  soil  extracted  with  water  with  20 
cubic  centimeters  of  distilled  water  and  5  cubic  centime- 
ters of  pure  bromine  free  from  sulphuric  acid  in  a  Bohe- 
mian glass  tube,  and  gradually  heat,  with  frequent 
shaking,  to  158°  F.  upon  the  water  bath.  By  the  bro- 
mine the  sulphur  present  is  oxidized  to  sulphuric  acid. 
When  entirely  cold  the  tube  is  opened  in  the  manner 
described  on  p.  84,  the  contents  are  rinsed  into  a  beaker, 
diluted  with  water,  and  heated  until  an  odor  of  bromine 
is  no  longer  perceptible.  Now  filter  the  soil  off,  and 
precipitate  the  sulphuric  acid  in  the  filtrate  in  the  above- 
mentioned  manner.  The  sulphuric  acid  obtained  from 
the  aqueous  extract  is  then  deducted  from  the  total  sul- 
phuric acid,  and  the  rest  calculated  to  sulphur  by  multi- 
plying it  by  the  factor  0.4. 


144  THE   EXAMINATION   OF   SOILS. 

In  the  presence  of  large  quantities  of  gypsum  this 
method  is  not  available,  as,  in  this  case,  all  the  sulphates 
are  not  extracted  by  the  aqueous  extract. 


IX. 

DETERMINATION  OF  VARIOUS  PROPERTIES  OF 
THE  SOIL  WHICH  ARE  DEPENDENT  PARTIALLY 
ON  PHYSICAL  AND  PARTIALLY  ON  CHEMICAL 
CAUSES. 

A.  Weight  of  the  soil. — We  distinguish  the  specific  grav- 
ity, and  the  absolute  volume  or  liter  weight  of  the  soil.  For 
determining  them  the  following  methods  are  suitable : — 

1.  Determination  of  the  specific  gravity. — A  thin  glass 
flask  of  about  100  cubic  centimeters  capacity,  and  pro- 
vided with  a  ground-glass  stopper,  drawn  out  to  an  open 
capillary  tube,  is  filled  up  to  the  end  of  the  capillary 
tube  with  distilled  water  of  60.8°  F.  The  flask  being 
carefully  cleansed  with  a  piece  of  leather,  is  then  accu- 
rately weighed  upon  a  chemical  balance.  The  flask  is 
then  emptied,  and  a  weighed  quantity  (about  20  gram- 
mes) of  the  soil  dried  at  212°  F.,  and  boiled  with  dis- 
tilled water  is,  when  cold,  introduced,  and  sufficient 
water  of  60.8°  F.  added  to  entirely  refill  the  flask.  It 
is  then  weighed.  By  adding  the  weight  of  the  soil  used 
to  the  weight  of  the  flask  filled  with  water  and  deduct- 
ing therefrom  the  weight  of  the  flask  filled  with  water 
and  the  soil,  the  difference  expresses  the  weight  of  a 
volume  of  water  which  is  equal  to  that  of  the  quantity 
of  soil  used.  Since,  by  this  means  the  proportion  of  the 


PROPERTIES   OF   THE   SOIL.  145 

weights  of  equal  volumes  of  soil  and  water  are  found, 
the  specific  gravity  of  the  soil  can,  therefrom,  be  de- 
duced by  dividing  the  weight  of  the  soil  with  the  weight 
of  the  water  it  has  displaced. 

2.  Determination  of  the  volume  ireiyht. — The  volume 
or  liter  weight  can  be  determined  in  two  ways,  by 
bringing  the  soil  into  a  measuring  vessel,  either  in  an 
air-dry  state,  or  saturated  with  water. 

Only  the  first-mentioned  method  is,  according  to  R. 
Heinrich's  experiments,  required  for  soils  containing  but 
little  humus,  it  yielding  nearly  the  same  results  as 
saturation  with  water. 

For  this  purpose  fill  a  measuring  cylinder  of  100 
cubic  centimeters  capacity,  with  air-dry  soil  pulverized 
as  uniformly  as  possible,  by  introducing  the  soil  in 
small  portions  and  compacting  it  by  gently  tapping  the 
vessel  upon  a  cork  support  until  a  diminution  in  volume 
no  longer  takes  place.  According  to  the  kind  of  soil, 
one-half  to  one  hour  will  be  required  for  this  process, 
care  being  taken  that  during  the  operation  the  measur- 
ing vessel  is  always  filled  with  soil  up  to  the  mark.  De- 
termine at  the  same  time  with  a  special  sample  the 
hygroscopic  water  which  escapes  at  212°  F.,  the  volume 
weight  ascertained  by  weighing  being  always  referred 
to  substance  dried  at  212°  F. 

By  dividing  the  volume  weight  of  the  soil  with  the 
weight  of  the  same  volume  of  water  the  apparent 
specific  gravity  of  the  soil  is  obtained. 

By  now  dividing  this  apparent  specific  gravity  with 

the  specific  gravity  of  the  soil,  the  quotient  expresses 

the  porosity  of  the  soil,  i.  e.}  the  space  which  in  soils  in 

a  dry  state  (its  volume  being  put  =  1)  is  occupied  by 

10 


146  THE   EXAMINATION   OF   SOILS. 

particles  of  air.  This  porosity  is  frequently  calculated 
to  100  parts  by  volume  of  the  soil. 

To  determine  the  volume  of  a  soil  completely  satu- 
rated with  water,  vigorously  shake,  according  to  E. 
Wolff,  25  to  30  grammes  of  finely  pulverized,  air-dry 
soil,  whose  volume  weight  is  known,  in  a  graduated 
tube  with  water  containing  1  per  cent,  of  sal  ammoniac, 
and  allow  to  settle.  The  volume  is  read  oif  after  twenty- 
four  hours.  lu  the  calculation  the  proportion  existing 
between  the  volume  of  soil  in  a  saturated  state  and  the 
same  volume  of  soil  in  a  dry  state  is  fixed  by  taking 
the  latter  as  the  unit. 

B.  Behavior  of  the  soil  towards  nourishing  substances. 
— The  power  of  the  soil  to  retain  separate  substances 
presented  to  it  in  solution  is  termed  absorption,  and  is 
dependent  partially  on  chemical,  and  partially  on  phy- 
sical causes,  though  opinions  differ  in  this  respect.  It  has 
been  ascertained  that  the  soil  takes  up  more  from  concen- 
trated than  from  more  dilute  solutions,  and  that  the 
absorbed  substances  can  be  again  partially  withdrawn 
from  the  soil  by  washing  with  much  water.  The  content 
of  humus  and  clay  has  great  influence  upon  the  ab- 
sorbent power  of  the  soil,  the  latter,  it  is  claimed,  being 
also  essentially  increased  by  .zeolitic  minerals. 

The  greater  or  smaller  absorbent  power  of  a  soil  being 
generally  in  direct  proportion  to  its  fertility,  a  determi- 
nation of  this  important  property  is  of  great  value,  since 
It  has  a  bearing  on  practical  agriculture,  especially  as  to 
the  rational  treatment  and  application  of  farm-yard 
manure  and  the  economical  use  of  artificial  manures. 

In  order  to  imitate  nature  as  closely  as  possible,  very 
dilute  nourishing  solutions  must  be  used  for  such  experi- 
ments. 


PROPERTIES   OF   THE   SOIL.  147 

1.  Testing  the  absorbent  power  of  the  soil  with  ^  or 
yJj-jj  normal  solutions. — For  making  these  experiments 
the  following  salts  are  very  suitable  :  Ammonium  chloride, 
potassium  nitrate,  calcium  nitrate,  magnesium  sulphate, 
and  monocalcium  phosphate. 

Ammonium  chloride,  calcium  nitrate,  and  magnesium 
sulphate  can  be  readily  prepared  as  chemically  pure 
anhydrous  salts,  and  in  this  state  weighed  in  a  closed 
weighing  tube.  The  T\y  normal  solution  of  these  salts 
is  prepared  as  follows :  Weigh  out  exactly  ^  of  their 
molecular  weight  in  grammes,  which  is  equivalent  to 
jJ-g-  of  the  atomic  weight  of  hydrogen  =  1,  and  dissolve  it 
in  1000  cubic  centimeters  of  distilled  water  of  60.8°  F. 
The  quantities  of  salt  required  for  1  liter  are  as  follows  : 
Ammonium  chloride=5.35  grammes,  potassium  nitrate 
=  10.11  grammes,  magnesium  sulphate=6.00  grammes. 

Since  calcium  nitrate  forms  a  very  deliquescent  salt, 
and,  therefore,  cannot  be  directly  weighed,  a  solution 
somewhat  more  concentrated  than  -fa  normal  solution  is 
prepared.  In  every  20  cubic  centimeters  the  content  of 
calcium  monoxide  is  determined  by  gravimetric  analysis, 
and  the  mean  of  two  determinations  taken  if  their  first 
decimals  agree.  Now  calculate  the  quantity  of  nitric  acid 
equivalent  to  the  calcium  monoxide,  and  compute  with 
how  many  cubic  centimeters  of  water  the  solution  pre- 
pared will  have  to  be  diluted  in  order  to  contain  8.2 
grammes  of  calcium  nitrate  in  1  liter. 

To  determine  the  absorption  of  phosphoric  acid,  mono- 
calcium  prosphate  (CaH4[POJ2-f  H2O)  is  very  suitably 
used,  this  soluble  phosphorus  salt  being  introduced  into 
the  soil  by  the  superphosphates  of  commerce.  For  its 
preparation  Fesca  proposes  the  following  method  :  Com- 


148  THE   EXAMINATION   OF   SOILS. 

pound  a  solution  of  commercial  sodium  phosphate  with 
glacial  acetic  acid,  precipitate  it  with  calcium  chloride 
solution,  and  wash  the  precipitate  by  decanting  until  the 
wash  water  shows  no  reaction  with  silver  nitrate.  Then 
bring  the  precipitate  in  a  moist  state  into  cold  concen- 
trated phosphoric  acid  until  saturated.  From  the  filtered 
solution,  in  a  heated  room,  the  monocalcium  phosphate 
separates  in  crystals  in  2  to  3  weeks.  The  crystals  are 
rinsed  off  with  anhydrous  ether,  pressed  between  blotting 
paper,  and  dried  over  sulphuric  acid. 

This  salt  being  soluble  without  decomposition  only  in 
a  very  dilute  solution,  Fesca  made  his  absorbent  experi- 
ments with  a  3-5^  atomic  solution  which  contained  in  1 
liter  of  water  2.5  grammes  of  monocalcium  phosphate 
corresponding  to  1.4  grammes  of  phosphoric  acid  (P2O4). 

The  coarser  admixtures  of  the  soil  possessing  no  ab- 
sorbent power,  soil  passed  through  a  0.5  millimeter  sieve 
is  always  used. 

For  the  determination  of  the  absorption,  50  grammes 
of  the  soil  are  left  in  contact  with  200  cubic  centimeters 
of  the  normal  solution  for  48  hours,  with  frequent 
shaking,  at  a  uniform  temperature  of  62.6°  F.  The 
soil  is  then  allowed  to  settle,  and  after  pouring  the  super- 
natant clear  solution  through  a  dry  filter,  the  substance, 
the  absorbed  quantity  of  which  is  to  be  learned,  is  deter- 
mined in  100  cubic  centimeters  of  the  filtrate.  Experi- 
ments have  shown  that  in  most  cases  it  suffices  to  deter- 
mine the  absorbent  power  of  the  soil  for  potassium? 
phosphoric  acid,  and  nitrogen.  In  order  to  proceed  as 
uniformly  as  possible  it  is  best  to  follow  Fesca's  pro- 
posal to  use  exactly  400  cubic  centimeters  of  normal  so- 
lution for  100  grammes  of  substance.  The  absorption- 


PKOPERTIES   OF   THE   SOIL.  149 

coefficient,  i.  e.,  the  quantity  of  the  absorbed  substance  in 
milligrammes  is  always  referred  to  100  grammes  of  air- 
dry  fine  earth  (less  than  0.5  millimeter  in  diameter). 

2.  Determination  of  the  absorption-coefficient  according 
to  Knop. — The  following  method  for  the  rapid  deter- 
mination of  the  absorption-coefficient  has  been  proposed 
by  Knop.  He  always  uses  for  the  experiments  air-dry 
fine  earth,  by  which  he  understands  the  portion  of  the 
soil  which  has  passed  through  a  wire  sieve  with  400 
meshes  to  the  square  centimeter.  When  using  a  sieve 
with  round  holes,  the  soil  passed  through  holes  0.5  milli- 
meter in  diameter,  though  somewhat  coarser  than  the 
material  used  by  Knop,  will,  according  to  Fesca,  be 
found  suitable  for  the  experiment. 

In  case  the  soil  is  very  binding  it  is  boiled  with  water 
and  passed  through  a  sieve  with  holes  0.5  millimeter  in 
diameter  with  the  aid  of  a  stiff  brush.  For  the  experi- 
ment use  50  or  100  grammes  of  the  perfectly  air-dry  fine 
earth  and  add  5  or  10  grammes  of  elutriated  powdered 
chalk.  Pour  over  this  mixture  in  a  cylindrical  vessel, 
which  can  be  effectually  closed,  a  solution  of  ammonium 
chloride  so  prepared  that  one  cubic  centimeter  of  it  on 
being  decomposed  with  sodium  bromide  evolves  exactly 
1  cubic  centimeter  of  nitrogen  (in  the  normal  state). 
Such  a  solution  is  obtained  by  dissolving  exactly  5 
grammes  of  freshly  sublimed  sal  ammoniac  in  1040  cubic 
centimeters  of  water  of  63.5°  F.  Now  add  to  50 
grammes  of  fine  earth  100,  or  to  100  grammes  of  fine 
earth,  200  cubic  centimeters  of  this  sal  ammoniac  solu- 
tion and  let  the  soil  remain  in  contact  with  it,  with  fre- 
quent shaking,  for  48  hours.  Then  allow  the  soil  to 
settle  and  pour  the  supernatant  clear  fluid  through  a  dry 


150  THE   EXAMINATION   OF   SOILS. 

filter.  From  the  filtrate  take  quickly,  by  means  of  a 
pipette,  20  or  40  cubic  centimeters,  and,  after  adding  one 
drop  of  pure  hydrochloric  acid,  evaporate  nearly  to  dry- 
ness  in  a  small  porcelain  dish  upon  the  water-bath. 
Rinse  the  sal  ammoniac  remaining  in  the  porcelain  dish 
with  10  cubic  centimeters  of  water  into  one  of  the  divis- 
ions of  the  developing  flask  of  the  Knop- Wagner  azot- 
ometer,  decompose  it  with  50  cubic  centimeters  of  bro- 
mine lye,  and  determine  the  nitrogen  volumetrically. 
The  volume  of  nitrogen  read  off  is,  with  due  considera- 
tion of  the  tension  of  the  aqueous  vapor,  the  height  of 
the  barometer,  and  the  temperature,  calculated  to  the 
normal  condition,  and  the  nitrogen  which  remains  ab- 
sorbed in  the  60  cubic  centimeters  of  fluid  (see  p.  118 
et  seq.}  added.  In  case  the  soil  possesses  no  absorption,  20 
or  40  cubic  centimeters  of  nitrogen  must  be  obtained. 
Knop  understands  by  absorption  the  loss  of  nitrogen 
which  200  cubic  centimeters  of  sal  ammoniac  solution 
suffer  when  in  contact  with  100  grammes  of  soil. 
Hence,  the  cubic  centimeters  of  nitrogen  determined  in 
the  azotometer  must  be  deducted  from  the  number  of 
cubic  centimeters  of  sal  ammoniac  solution  used,  and  the 
difference  calculated  to  100  grammes  of  air-dry  soil  less 
than  0.5  millimeter  in  diameter. 

For  judging  the  fertility  of  a  soil  the  determination  of 
Knop's  absorption-coefficient  is  of  great  value,  since, 
though  in  exceptional  cases  an  entirely  unproductive  soil 
may  happen  to  possess  great  absorption,  a  soil  with  slight 
absorption  can  never  be  classed  with  very  fertile  soils. 
Knop  considers  absorptions  of  from  0  to  5  degrees  as 
insufficient,  of  from  5  to  10  as  sufficient,  while  those  of 


PROPERTIES   OF   THE  SOIL.  151 

from  10  to  10  higher  degrees  progressively  increase  the 
value  of  the  soil. 

In  the  valuation  of  the  soil  by  absorption,  it  must 
always  be  borne  in  mind  that  it  would  be  entirely  wrong 
to  judge  the  soil  by  this  property  alone,  since  a  single 
property  favorable  for  the  soil  may,  as  regards  its  value, 
be  entirely  nullified  by  others  exerting  an  unfavorable  in- 
fluence. 

C.  Behavior  of  the  soil  towards  water.  1 .  The  power 
of  retaining  moisture  in  the  soil. — The  amount  of  moisture 
retained  by  a  soil  is  generally  in  direct  ratio  to  its  con- 
tents of  organic  matter  and  its  state  of  division.  A 
proper  degree  of  fineness  in  the  particles  of  the  soil  is 
very  important  to  obtain,  especially  if  it  is  subjected  to 
drought.  During  dry  weather  plants  require  a  soil  that 
is  both  retentive  and  absorptive  of  atmospheric  moisture, 
and  that  soil  which  has  this  faculty  will  evidently  raise 
a  more  vigorous  crop  than  one  without  it.  Regarding 
this  condition  of  retaining  moisture,  the  materials  which 
are  most  influential  in  soils  may  be  arranged  in  the  fol- 
lowing order :  Organic  matter,  marls,  clays,  loams,  and 
sands.  For  the  determination  of  the  power  of  the  soil 
to  retain  moisture  the  following  methods  may  be  men- 
tioned : — 

a.  By  experiments  in  the  laboratory. — Pour  over  100 
grammes  of  the  air-dry  fine  soil  100  cubic  centimeters 
of  distilled  water  and  effect  the  thorough  saturation  of  the 
soil  by  stirring  with  a  glass  rod.  Now  rinse  the  soil 
with  100  cubic  centimeters  of  water,  admitted  from  a 
pipette,  upon  a  filter  saturated  with  water.  The  water 
running  off  is  caught  in  a  graduated  cylinder  of  200 
cubic  centimeters  capacity,  and  when  nothing  more  drips 


152  THE    EXAMINATION    OF   SOILS. 

off,  the  quantity  is  read  off  in  cubic  centimeters.  The 
difference  between  the  quantity  of  water  used  (200  cubic 
centimeters)  and  that  caught  corresponds  to  the  quantity 
of  water  retained  by  the  soil.  This  behavior  of  the  soil, 
which  corresponds  to  its  comparatively  highest  degree 
of  looseness,  has  been  designated  the  greatest  or  full 
capacity  for  water.  It  is  calculated  for  100  parts  by 
weight,  as  well  as  for  one  liter  of  the  soil  dried  at 
212°  F. 

This  full  capacity  may  also  be  determined  as  follows : 
Stir  up  100  grammes  of  the  air-dry  soil  (less  than  2 
millimeters  in  diameter)  in  the  above-mentioned  manner 
with  any  desired  quantity  of  water  in  excess,  and  bring 
the  whole  with  the  aid  of  a  wash-bottle  into  a  previously 
weighed  funnel  in  the  point  of  which  a  small  filter  is  in- 
serted. Cover  the  funnel  with  a  watch  crystal,  and 
when,  after  standing  for  some  time,  no  more  water  drips 
off,  weigh  it.  Both  these  methods  are  quite  suitable  for 
very  pervious  soils,  but  with  very  clayey  or  humus  soils 
have  the  disadvantage  that  the  dripping  off  of  water 
already  ceases  when  the  mass  in  the  filter  is  still  in 
a  thinly-pasty  condition. 

Since,  in  order  to  obtain  accurate  comparable  results, 
it  is  necessary  for  the  samples  of  soil  to  be  always  in  the 
same  state  of  looseness,  a  method  for  laboratory  experi- 
ments has  been  proposed  by  which  this  is  sought  to  be 
attained  as  nearly  as  possible.  For  this  purpose  cylin- 
drical tubes  of  zinc  sheet  (Fig.  23),  exactly  16  centi- 
meters long  and  4  centimeters  in  diameter,  are  used. 
Their  volume  would,  therefore,  be  201.06  cubic  centi- 
meters. The  bottom  of  the  tube  consists  of  fine  nickel  wire 
gauze.  Below  the  gauze  a  piece  of  zinc  tube  perforated 


PROPERTIES   OF   THE   SOIL.  153 

on  the  sides  is  soldered  over  it.  Before  use  a  piece  of 
moistened  fine  linen  is  placed  upon  the  Mrire  gauze 
bottom,  and  after  tying  a  piece  of  rubber  over  the  lower 
end,  the  lower  portion  of  the  cylinder  is  filled  with  water 

Fig.  23. 


up  to  the  gauze  bottom.  Now  pour  200  cubic  centimeters 
of  water  of  60.8°  F.  into  the  cylinder  and  make  a  mark 
exactly  over  the  level  of  the  water.  The  edge  of  zinc 
sheet  above  this  mark  is  filed  off,  so  that  the  cylinder 
with  the  linen  rag  has  a  capacity  of  exactly  200  cubic 
centimeters,  and  may,  at  the  same  time,  be  used  for  the 
determination  of  the  volume  weight  of  the  soil.  After 
placing  the  moist  linen  rag  in  the  cylinder  the  latter  is 
first  weighed  and  then  filled,  constantly  tapping  it  against 
a  soft  support,  with  the  uniformly  divided  air-dry  soil. 
The  soil  is  finally  accurately  leveled  with  a  knife.  The 
cylinder  is  again  weighed  and  then  placed  in  a  glass  dish 
containing  water,  so  that  the  gauze  bottom  dips  about  4 
to  5  millimeters  in  the  water.  Over  several  tubes  thus 
prepared  a  heavy  glass  bell  shutting  out  the  air  is  placed. 
In  this  manner  the  soil  is  then  allowed  to  absorb  wat$r 
from  below  until  saturated.  According  to  the  condition 
of  the  soil,  its  saturation  with  moisture  will  be  observed 
on  the  surface  in  a  longer  or  shorter  time.  The  cylinders 
are  allowed  to  remain  under  the  glass  bell  until  after 


154  THE   EXAMINATION   OF   SOILS. 

repeated  weighing,  for  which  purpose  they  are  placed  in 
a  shallow  porcelain  dish,  they  show  an  approximately 
constant  weight.  In  weighing  the  temperature  and 
height  of  the  barometer  are  to  be  observed.  The  in- 
crease in  weight  corresponds  to  the  total  quantity  of 
water  absorbed  which  can  be  directly  calculated  for  the 
volume  of  soil. 

Another  method  corresponding  still  more  to  the 
natural  conditions  has  been  used  by  A.  Mayer.  He 
uses  two  glass  tubes  0.75  and  0.25  meter  long,  and  2 
centimeters  in  diameter.  The  upper  shorter  end  is  con- 
nected with  the  longer  by  a  short  rubber  tube.  The 
lower  end  of  the  long  tube  is  closed  by  tying  a  piece  of 
linen  over  it.  The  tubes  are  then  filled  with  air-dry 
fine  soil,  they  being  gently  tapped  against  a  soft  support 
during  the  operation.  Then  pour  enough  water  upon 
the  soil  transitorily  to  establish  its  full  capacity  for 
water.  By  now  waiting  for  some  time  the  column  of 
water  sinks  down.  When  no  more  water  drips  off  be- 
low, the  rubber  tube  is  disconnected,  and  on  this  place  a 
sufficient  quantity  of  'soil  is  taken  out,  quickly  weighed, 
and  the  water  retained  by  it  determined  by  drying  at 
212°  F.  With  the  assistance  of  the  apparent  specific 
gravity  (p.  145),  the  capacity  for  water  of  the  weight  of 
soil  can  be  calculated  to  the  volume  of  soil.  To  the 
smallest  quantity  of  water  retained  by  the  soil  thus 
obtained,  Mayer  has  applied  the  term  absolute  capacity 
for  water.  On  account  of  their  very  slight  permea- 
bility this  method  cannot  be  used  with  very  clayey 
soils. 

6.  Determination  of  the  water  capacity  of  tJie  soil  in  its 
natural  bed  in  the  open  field. — The  following  process  was 


PROPERTIES   OF   THE   SOIL.  155 

devised  by  R.  Heinrich,  and  deserves  to  be  preferred  to 
the  experiments  in  the  laboratory.  To  saturate  the  soil 
in  its  natural  bed  in  the  field,  a  round  sheet-metal  cylin- 
der, 20  cubic  centimeters  in  diameter  and  40  centimeters 
long,  is  used.  The  lower  end  of  the  cylinder  consisting 
of  strong  sheet  iron  is  sharpened  and  forced  into  the  soil 
by  means  of  the  feet.  For  this  purpose  the  cylinder  is 
on  both  sides  provided  with  a  ledge,  while  to  diminish 
the  fall  of  the  water  to  be  poured  in  and  not  to  mechan- 
ically reduce  the  soil  to  mud,  a  fine  sieve  is  placed  in  the 
upper  portion  of  the  cylinder.  When  the  cylinder  has 
been  firmly  forced  into  the  soil  so  that  no  water  can  run 
out  on  the  side,  it  is  entirely  filled  with  water.  The 
water  is  then  allowed  to  soak  into  the  soil,  the  latter 
being  covered  with  a  board  or  sheet  of  parchment  paper 
to  protect  it  against  evaporation  and  other  influences. 
Sample  taking  is  effected  after  18  to  24  hours,  since  only 
then,  according  to  Heinrich's  experiments,  the  quantity 
of  water  retained  remains  constant  for  some  time.  After 
removing  the  cylinder,  dig  out  with  a  spade  the  soil  up 
to  the  centre  of  the  spot  terminated  by  the  cylinder, 
using,  however,  the  precaution  of  gently  forcing  the 
surface  of  the  spade  away  from  the  sample  to  be  taken. 
The  uppermost  layer  of  soil,  from  2  to  4  centimeters 
thick,  is  removed,  a  piece  cut  out  of  the  centre  with  a 
knife,  brought  into  a  powder  flask  of  known  weight  and 
hermetically  closed.  The  quantity  of  water  which  the 
soil  retains  is  determined  by  continuous  drying  at  212° 
F.  of  the  weighed  sample  in  the  flask  and  calculated  to 
100  grammes  as  well  as  to  1  liter  of  soil.  Small  stones 
over  0.5  centimeter  in  diameter  contained  in  the  sample 
are  later  on  sorted  out  and  their  weight  deducted.  The 


156  THE    EXAMINATION   OF   SOILS. 

small  quantity  of  water  adhering  to  these  stones  need 
not  be  noticed. 

The  method  just  described  has  later  on  been  modified 
by  Heinrich  so  that  the  soil  is  lifted  out  to  the  sub-soil 
and  the  cylinder  placed  upon  the  sub-soil.  The  top  soil 
is  then  replaced  in  its  former  position  outside  the  sheet- 
metal  cylinder,  while  the  rest  of  the  soil  is  rubbed  through 
the  sieve  with  as  little  water  as  possible,  so  that  all  the 
coarser  stones  remain  behind.  For  the  determination  of 
water  the  soil  is,  after  about  24  hours,  lifted  out  with  a 
gouge-bit,  the  lower  opening  of  which  corresponds  to  a 
surface  of  1  square  centimeter. 

2.  The  evaporating  power  of  the  soil. — In  determining 
the  evaporating  power  of  the  soil,  it  must  also  be  sought 
to  imitate  as  closely  as  possible  the  natural  conditions  by 
exposing  a  sufficiently  thick  layer  of  soil  to  the  alterna- 
ting influence  of  the  direct  rays  of  the  sun  and  to  the 
shade.  It  is  best  to  use  for  this  purpose  the  cylindrical  zinc 
tubes  with  sieve  bottoms  described  on  p.  152.  According 
to  E.  Wolff,  they  are  surrounded  with  a  narrow  shell  of 
thick  paste-board,  and,  after  being  filled  with  soil  in  a 
state  of  full  water  capacity,  are  placed  alongside  each 
other  in  a  small  wooden  box  whose  shiftable  lid  is  pro- 
vided with  apertures  corresponding  to  the  diameter  of 
the  cylinders,  so  that  the  lateral  radiation  of  the  sun  is  en- 
tirely shut  out.  This  box  is  placed  in  the  open  air,  the 
zinc  tubes  being  taken  from  the  paste-board  shells  every 
24  hours  and  their  decrease  determined  by  weighing, 
whereby  the  temperature  of  the  surrounding  air,  its 
moisture,  the  height  of  the  barometer  at  the  time  being, 
and  the  cloudy  or  cloudless  state  of  the  sky  have  to  be 
noted.  Since  the  weight  of  the  air-dry  soil  used,  as  well 


PROPERTIES   OF   THE   SOIL.  157 

as  the  largest  quantity  of  water  retained  by  it,  is 
known,  the  evaporating  capacity  can  be  given  either  in 
per  cent,  of  the  substance  dried  at  212°  F.,  or  in  per 
cent,  of  the  total  quantity  of  water  absorbed. 

3.  The  filtrating  power  of  the  soil. — By  the  filtrating 
power  of  the  soil  is  understood  its  property  of  allowing  the 
water  to  percolate  in  a  longer  or  shorter  time.  To  de- 
termine this,  a  square  zinc  box  25  centimeters  high  and 
3  centimeters  wide,  provided  below  with  a  funnel- 
shaped  piece  with  discharge-pipe,  is,  according  to  E. 
AYolff,  employed.  The  discharge-pipe  of  the  funnel- 
shaped  piece  is  closed  with  cotton,  projecting  somewhat 
from  the  pipe.  The  funnel-shaped  piece  is  filled  with 
coarse  quartz  sand.  The  cotton  and  sand  are  saturated 
with  water,  when  the  apparatus  is  weighed.  Now  bring 
into  the  box,  tapping  it  constantly  against  a  soft  support, 
a  layer  of  air-dry  soil  16  centimeters  thick,  and  weigh. 
Then  pour  wrater  over  the  soil  and  again  weigh  the  box 
wrhen  no  more  dripping  off  takes  place.  Thus  the  full 
water  capacity  is  obtained. 

Now  pour  upon  the  soil,  without  stirring  it  up,  a  layer 
of  water  8  centimeters  deep  and  determine  how  much 
time  it  takes  until  no  more  dripping  off  from  the  dis- 
charge-pipe takes  place.  The  filtering  capacity  of  this 
layer  of  soil  16  centimeters  thick,  and  in  a  state  of  full 
water  capacity  for  a  column  of  water  8  centimeters  high, 
is  given  in  feet.  Since,  however,  in  repeating  the  ex- 
periment more  time  is  almost  always  consumed  in  filter- 
ing than  in  the  first  trial,  the  experiment  has  to  be  repeated 
five  or  six  times,  and  the  mean  of  the  results  taken. 
For  very  clayey  soils  this  method  is  not  available,  since 


158 


THE   EXAMINATION   OF  SOILS. 


the  water  poured  upon  the  soil  remains  standing  without 
running  off. 

The  experiment  may  also  be  made  by  each  time  allow- 
ing exactly  50  centimeters  to  drop  into  a  graduated 
cylinder  and  noting  the  time  thereby  consumed. 

4.  Capillary  attraction  of  the  soil. — To  determine  the 
capillary  attraction  by  experiment,  the  lower  ends  of 


glass  tubes  each  100  centimeters  long  and  2  centimeters 
in  diameter,  a-re  closed  with  fine  muslin  by-drawing  a 
rubber  ring  over  them,  D  (Fig.  24).  Fill  the  tubes, 
tapping  them  gently,  with  air-dry  fine  soil  (less  than  2 
millimeters  in  diameter),  and  insert  them  1  to  2  centi- 


PROPERTIES   OF   THE   SOIL.  159 

metres  deep  in  a  glass  dish,  B  (Fig.  24),  containing 
water.  It  is  recommended  to  use  for  the  experiment 
the  stand  A  (Fig.  24),  which  is  arranged  for  ten  tubes, 
C,  which,  in  order  to  keep  them  suspended  in  the  water, 
are  above  secured  by  rubber  rings,  E. 

With  the  aid  of  a  meter  rule  it  is  now  ascertained 
how  much  time  the  fluid  consumes  in  ascending  20,  30, 
40,  50,  60,  70  centimeters,  and  in  what  time  the  maxi- 
mum ascent  is  reached.  The  water  absorbed  by  the  soil 
from  the  glass  dish  B  must  constantly  be  replaced. 

The  experiment  may  also  be  made  by  measuring  the 
heights  to  which  the  fluid  has  risen  in  24,  48,  72,  96, 
1 20  hours. 

When  the  experiment  is  finished,  it  is  also  of  interest 
to  cut  up  the  tubes  into  pieces  1  decimeter  long,  and  to 
separately  determine  the  content  of  water  in  them.  It 
may  here  be  remarked  that  the  tubes  of  100  centimeters 
length  may  also  be  used  for  the  purpose  of  determining 
how  deeply  and  rapidly  a  column  of  water  of  determined 
height  (for  instance,  10  centimeters)  penetrates  from  above 
into  the  air-dry  soil. 

D.  Behavior  of  the  soil  towards  gases.  1 .  The  absor- 
bent capacity  of  the  soil  for  aqueous  vapor. — To  determine 
the  saturation-degree  of  the  soil  in  a  space  filled  with 
aqueous  vapors,  bring  10  grammes  of  the  air-dry  soil 
into  a  shallow  zinc  box  with  a  bottom-surface  of  25 
square  centimeters,  spreading  it  out  as  uniformly  as 
possible.  After  weighing  the  box  with  the  soil,  place 
another  weighed  box  of  the  same  size,  but  empty,  to- 
gether with  the  first,  upon  a  tripod  under  a  glass  bell 
dipping  in  water.  In  the  glass  bell  hang  a  thermo- 
meter, and  at  each  weighing  read  off  the  temperature. 


160  THE   EXAMINATION   OF  SOILS. 

After  24  hours  weigh  the  zinc  box  filled  with  soil,  as 
well  as  the  empty  one,  and  deduct  the  increase  in  weight 
of  the  latter  from  the  increase  in  weight  of  the  former. 
Repeat  the  weighings  at  intervals  of  24  hours,  until, 
with  the  same  conditions  of  temperature,  an  approxi- 
mately constant  weight  is  obtained.  The  moisture 
retained  is  calculated  for  100  grammes  of  the  soil  dried 
at  212°  F.,  and  designated  as  the  absorbent  capacity  for 
aqueous  vapor. 

2.  The  absorbent  power  of  the  soil  for  the  oxygen  of  the 
atmospheric  air. — The  absorbent  power  of  the  soil  for 
oxygen  is  traceable  to  chemical  and  physical  causes.  Its 
fixation  chemically  i»  effected  by  the  oxidation  of  ferrous 
oxide  combinations,  metallic  sulphides,  and  humus  sub- 
stances which  may  be  present  in  the  soil.  The  physical 
absorption  is  dependent  on  the  condensation  of  the  gas 
upon  the  surface  of  the  particles  of  soil.  The  chemical 
fixation  of  the  oxygen  preponderates  by  far,  and  from  it 
a  judgment  can  frequently  be  formed  regarding  the  con- 
dition of  the  humus  substances,  they  being  found  in  the 
soil  in  a  more  or  less  readily  decomposable  state  corre- 
sponding to  the  greater  or  smaller  absorption  of  oxygen. 
According  to  W.  Wolf,  50  or  100  grammes  of  soil  are 
compounded  with  so  much  distilled  water  that  the  soil 
to  be  examined  contains  20  per  cent,  of  it.  The  soil  is 
enclosed,  together  with  an  accurately  measured  quantity 
of  air,  in  bottles  of  500  centimeters  capacity,  and  the 
change  in  the  volume  of  air  in  from  8  to  14  days  ob- 
served, the  quantity  of  carbonic  acid  formed  in  place 
of  the  oxygen,  which  has  disappeared,  being  at  the  same 
time  determined. 

If  simply  the  absorption-coefficient  of  the   soil    for 


PROPERTIES   OF   THE   SOIL.  161 

oxygen  is  to  be  determined,  thoroughly  moisten,  accord- 
ing to  F.  Sclmlze,  25  grammes  of  soil  in  a  small  flask 
with  quite  concentrated  potash  lye,  connect  the  flask 
with  an  azotometer  in  which  a  determined  volume  of  air 
is  shut  off  by  mercury  and  repeatedly  shake  the  flask 
during  the  experiment.  The  decrease  (after  one  to  four 
days)  in  the  volume  of  air  contained  in  the  entire 
apparatus  gives  the  quantity  of  oxygen  absorbed. 

G.  Ammon,  in  his  article  "  Untersuchuugen  iiber 
das  Condensationsvermogen  der  Bodenkonstituenten  fur 
Gas,"*  sums  up  the  most  interesting  results  of  his  ex- 
periments as  follows  : — 

1.  The  condensation  of  the  gases  by  the  soil  is  de- 
pendent on  physical  and  chemical  processes. 

2.  The  absorption  of  gas  in  the  soil  brought  about 
by  chemical  processes  is  of  greater  moment  than  that 
caused  by  surface  attraction.     The  former  is  principally 
effected  by  the  ferric  oxide  and  next  by  the  humus  sub- 
stances. 

3.  The  gases  in  being  condensed  by  the  soil  are  either 
absorbed    as    such,   or    they   suffer    thereby   chemical 
changes. 

4.  The  gases  are  generally  condensed  in  a  higher  de- 
gree the  more  readily,  they  otherwise  change  their  aggre- 
gate state  and  the  more  readily  they  are  decomposed. 

5.  The  condensation  of  the  gases  in  the  soil  is  the 
greater,  the  finer,  under  otherwise  equal  conditions,  the 
particles  of  soil  are. 

6.  The  largest  quantities  of  gases  are  condensed  by 
the  soil  at  a  temperature  between  zero  and  10°  C.,  while 

*  Wollny,  Forschungen  auf  dem  Gebiete  der  Agrikultur-Physik. 
Band  II.,  1879. 
11 


162  THE   EXAMINATION    OF   SOILS. 

from  that  point  on,  the  quantity  of  gases  absorbed  de- 
creases with  the  rise  and  fall  of  temperature. 

3.  The  ventilating  power  of  the  soil. — The  ventilating 
power  of  a  soil,  i.  e.,  the  greater  or  smaller  resistance 
opposed  by  different  soils  in  a  wet  state  to  the  passage 
of  the  air,  has  been  justly  considered,  by  R.  Heinrich, 
as  a  very  important  property  for  j  udging  of  it.  Whether 
drainage  can  be  carried  out  in  a  field  or  not  is  solely 
dependent,  it  is  claimed,  on  this  property. 

The  experiment  is  made,  according  to  Heinrich,  as 
follows  :  After  the  soil  has  been  saturated  by  means  of 
the  sheet  cylinder  described  on  p.  155,  under  determina- 
tion of  the  water  capacity  in  the  open  field,  and  a  con- 
stant water  capacity  has  been  obtained,  a  square  box  o 
strong  zinc  sheet  C  (Fig.  25),  100  square  centimeters  in 
cross-section  and  20  centimeters  high,  is  10  centimeters 
deep  sunk  into  the  soil.  On  the  outside  of  the  box,  10 
centimeters  from  the  bottom,  a  strip  of  zinc  sheet,  5  cen- 
timeters wide,  is  soldered  on  at  a  right  angle,  so  that  by 
this  means  the  box  can  be  forced  by  the  foot  into  the 
soil  to  the  above-mentioned  depth,  and,  therefore,  in- 
closes a  cube  of  earth  of  1000  cubic  centimeters.  The 
portion  of  the  box  above  the  soil  serves  as  an  air- 
chamber  and  is  connected  with  the  flask  B,  of  ten  liters 
capacity,  by  a  tube  soldered  on,  on  the  side.  By  the  ad- 
mission of  water  by  means  of  a  siphon  from  the  flask  A, 
standing  at  a  higher  level,  into  the  flask  B,  the  air  in  the 
latter  is  compressed  and  forced  through  the  soil.  The 
flask  jB  is  provided  with  a  manometer,  D,  by  which  the 
air-pressure  can  be  measured.  By  raising  or  lowering 
the  wrater  reservoir  A,  the  air-pressure  can  be  increased 
or  decreased  at  will. 


PROPERTIES   OF    THE   SOIL. 


163 


In  making  the  experiment,  water  is  allowed  to  flow 
in  until  the  manometer  shows  the  desired  pressure. 
Then  shut  off  the  water  by  closing  the  clip  and  wait  one 
or  two  minutes.  If  the  pressure  decreases  during  this 

Fis.  25. 


tim  admit  more  water  until  the  first  pressure  has  been 
again  attained.  By  continuing  the  experiment  in  this 
manner,  the  time  required  to  force  10  liters  of  air,  at  a 
determined  height  of  the  manometer,  through  1  liter  of 
soil  is  ascertained. 

E.  Behavior  of  the  soil  towards  heat.  1.  Determina- 
tion of  the  heat-absorbent  y>ower  of  the  soil. — A  cylindrical 
glass  vat  4  centimeters  high  and  16  centimeters  in 
diameter,  covered  outside  with  thick  asbestos  pasteboard, 
is  entirely  filled  with  air-dry  fine  soil,  then  placed  in  a 
wooden  box  the  lid  of  which  is  provided  with  an  aper- 
ture corresponding  to  the  cross-section  of  the  glass  vat 


164  THE   EXAMINATION   OF   SOILS. 

and  exposed  for  6  hours  to  the  direct  rays  of  the  sun. 
By  a  maximum  thermometer,  imbedded  1  centimeter 
deep  in  the  soil,  the  temperature  to  which  the  soil  during 
this  time  has  been  heated  is  then  ascertained.  The  ex- 
periment is  repeated  under  as  equal  conditions  as  pos- 
sible by  imbedding  the  thermometer  2,  3  and  4  centime- 
ters deep  and  determining  the  maximum  temperature  to 
which  the  soil  has  been  heated. 

The  heating  capacity  of  a  soil  is  dependent  on  various 
conditions.  The  specific  heat  of  the  soils,  i.  e.,  their  dif- 
ferent behavior  regarding  the  absorption  of  varying 
quantities  of  heat  units  to  increase  their  temperature  1° 
C.,  will  have  to  be  taken  into  consideration,  further  their 
color  and  their  more  or  less  inclined  position. 

With  soils  saturated  with  moisture  as  found  in  the 
field,  their  greater  or  smaller  content  of  water  is,  how- 
ever, of  the  greatest  importance  as  regards  the  absorp- 
tion of  heat.  While  1  kilogramme  of  water  requires  100 
units  of  heat  to  be  raised  1°  C.,  an  equal  weight  of  clay 
requires  only  17.8,  and  an  equal  weight  of  sand  only  12.8 
units  of  heat  for  the  same  increase  in  temperature.  To 
this,  it  must  further  be  added,  that  a  moist  soil  is  con- 
siderably cooled  off  by  the  evaporation  taking  place  on 
its  surface.  Hence,  a  field  suffering  from  moisture  may 
always  be  designated  as  cold. 

Investigations  regarding  the  maximum  and  minimum 
temperatures  of  the  soil  in  a  day,  week  or  month  are  of 
great  value  when  the  results  are  compared  with  the  tem- 
peratures of  the  air  at  the  time  being  and  referred  to  the 
plant-production  of  the  soil.  It  is  best  to  use  for  this 
purpose  maximum  and  minimum  thermometers  accord- 


PROPERTIES   OF   THE   SOIL.  165 

ing  to  the  Six-Kapeller  system,  which  are  imbedded  1, 
2,  5,  10  centimeters  deep  in  the  soil. 

2.  The  heat-conducting  power  of  the  soil. — The  heat- 
conducting  power  of  the  soil  is  determined  by  filling, 
with  constant  tapping  against  a  soft  support,  -a  thin 
spherical  glass  flask  of  1  liter  capacity  with  air-dry  fine 
soil  and  at  the  same  time  fixing  the  bulb  of  a  mercury 
thermometer  in  the  centre  of  the  flask.  The  latter  is 
then  brought  into  a  drying  chamber  provided  with  a 
gas-pressure  regulator  and  heated  to  212°  F.  Now 
accurately  observe  the  time  required  to  heat  the  soil  to 
its  centre  from  its  original  temperature  to  212°  F. 

The  experiment  may  also  be  made  by  heating  the  soil 
in  the  same  vessel  to  212°  F.  and,  determining,  by  the 
thermometer  sticking  in  the  soil,  the  time  required  for 
the  soil  to  cool  off  to  its  initial  temperature. 

From  his  experiments  Wollny  has  deduced  the  follow- 
ing general  results  : — 

1.  During  the  warmer  season  of  the  year  and  with 
warm  weather,  a  compact  soil  is  on  an  average  warmer 
than  a  loose  soil. 

2.  During  the  colder  seasons  of  the  year  (spring  and 
fall),  and  also  in  the  warmer  season,  whenever  there  is  a 
sudden  and  considerable  fall  in  the  temperature,  a  com- 
pact soil  is,  on  an  average,  colder  than  a  loose  soil. 

3.  During  the  warmer  season  of  the  year,  and  with 
warm  weather,  a  compact  soil  is  considerably  warmer 
during  the  day,  but  commonly  colder  during  the  night 
than  a  loose  soil. 

4.  At  the  time  of  the  daily  maximum  of  the  tempera- 
ture of  the  soil  the  difference  mentioned  under  1   is 
greatest,  but  at  the  time  of  the  daily  minimum,  either 


166  THE   EXAMINATION   OF   SOILS. 

very  small  or  an  equalization  or  even  an  inverse  ratio 
takes  place. 

5.  In  a  compact  soil  the  variations  in  temperature  are 
considerably  greater  than  in  a  loose  soil. 

6.  The  causes  of  the   above-mentioned   phenomena 
are  due  to  the  better  heat-conducting  power  of  a  com- 
pact soil  as  compared  with  a  loose  soil. 

F.  Cohesion  and  adhesion  of  the  soil. — To  determine 
the  degree  of  firmness  with  which  the  particles  of  soil 
in  a  dry  state  cohere  together,  knead,  according  to  the 
method  proposed  by  Schiibler,  the  soil  together  with 
water  and  shape  the  mixture  in  a  mould  to  rods  5  centi- 
meters long  and  1  centimeter  wide.  After  completely 
drying  the  rods  in  the  air,  the  pressure  required  to  cut 
them  through  is  determined  by  placing  weights  upon  a 
suitable  apparatus  provided  below  with  a  dull  edge. 

Another  method  to  determine  the  coherence  of  the 
soil  in  a  wet  state  was  devised  by  R.  Heinrich.  The 
soil  is  uniformly  saturated  with  water  so  that  the  con- 
tent of  water  amounts  to  exactly  50  per  cent,  of  the 
highest  water-capacity  of  the  experiment  in  the  labora- 
tory. The  soil  is  then  pressed  between  two  sheet-iron 
plates,  one  side  of  which  is  in  the  centre  provided  with 
a  hook.  The  layer  of  soil  between  the  sheet-iron  plates 
should  be  from  5  to  10  centimeters.  The  upper  plate 
is  then  suspended  from  a  thread,  while  to  the  lower  a 
small  basket  is  secured,  into  which  sand  in  small  portions 
is  introduced  until  the  column  of  soil  tears  apart.  The 
plate  torn  away,  together  with  the  basket  and  the  ad- 
hering soil,  is  then  weighed.  Their  weight  corresponds 
to  the  force  required  to  break  up  the  coherence  of  a  layer 
of  earth  one  decimeter  in  cross-section.  This  method 


GENERAL   RULES   FOR   SOIL- ANALYSIS.  167 

is,  of  course,  only  available  for  soils  in  which  the  ad- 
hesion to  the  iron  plate  is  greater  than  the  coherence  of 
the  soil. 

Regarding  the  adhesion  of  moist  soils  to  iron  and 
wood,  the  sample  to  be  examined  is,  according  to  Hein- 
rich's  directions,  also  moistened  with  50  per  cent,  of 
water  of  its  highest  water  capacity,  and  after  bringing  it 
into  a  larger  vessel,  the  surface  of  the  soil  is  leveled  as 
much  as  possible.  A  plate  of  sheet-iron  or  beech  wood 
one  square  decimeter  in  cross-section  is  then  pressed 
firmly  upon  the  soil,  so  that  a  complete  contact  of  the 
soil  with  the  metal  or  wood  takes  place.  To  the  hook 
of  the  plate  is  fastened  a  cord  which  runs  over  a  pulley 
and  carries  a  small  basket.  The  latter  is  loaded  with 
sand  until  the  plate  tears  loose  from  the  soil.  The 
force  required  to  overcome  the  adhesion  corresponds  to 
the  weight  of  the  basket  and  of  the  portion  of  cord 
reaching  to  the  summit  of  the  pulley,  less  the  weight  of 
the  plate  torn  off  and  the  other  end  of  the  cord. 


X. 

GENERAL  RULES  FOR   SOIL-ANALYSIS. 

IT  is,  of  course,  self-evident  that  in  the  examination 
of  determined  varieties  of  soil  not  all  the  methods  dis- 
cussed in  the  preceding  sections  will  need  to  be  employed. 
The  course  of  soil-analysis  cannot  be  regulated  accord- 
ing to  a  pattern  with  fixed  limits,  but  must,  in  each 
case,  be  adapted  to  the  questions  to  be  decided.  How- 
ever, in  order  to  obtain  comparable  results,  it  is  necessary 


168  THE   EXAMINATION   OF  SOILS. 

to  agree  on  certain  fixed  rules.  Proceeding  from  the 
point  of  view  that  the  chief  purpose  of  soil-analysis  is 
to  be  of  service  to  agriculture  and  forestry,  the  general 
rules  to  be  applied  to  the  examination  of  soils  and  the 
question  which  deserves  special  consideration  shall  here 
be  briefly  summed  up  : — 

1.  The  profile  of  the  entire  soil,  as  far  as  of  importance 
for  the  nourishment  of  plants,  must  be  included  in  the 
examination.     This,  in  most  cases,  will  embrace  the  top- 
soil  and  the  more  shallow  and  deeper  subsoils. 

2.  Whenever  possible,  accurate  analyses  by  graining 
with  the  round-hole  sieve  and  elutriating  with  Schoene's 
apparatus  should   be  executed  with   the  three  above- 
mentioned  layers  of  soil,  and  always  with  the  top-soil  if 
not  derived  from  moor-soil.     From  such  analyses  im- 
portant conclusions  regarding  the  physical  properties  of 
the  top-soil  and  subsoil  can  be  drawn,  and  a  thorough  . 
knowledge  of  the  mechanical  mixture  of  the  soil  is  of 
great  value  for  judging  it.     For  the  mechanical  analysis 
the  air-dry  total  soil  is  to  be  used. 

3.  For  judging  the  subsoil,  it  is  further  of  import- 
ance to  determine  its  content  of  carbonate  of  lime,  as 
well  as  of  clay,  the  latter  by  disintegration  of  the  clayey 
particles,  less  than  0.5  millimeter  in  diameter,  with  sul- 
phuric acid  in  the  closed  tube  (p.  83). 

4.  If  the  layers  of  the  subsoil  are  to  be  utilized  for 
meliorating  purposes,  they  must  be  examined  as  to  the 
substances  useful  and  injurious  to  the  growth  of  plants 
contained  in  them.     Of  the  useful  substances,  it  will 
be  primarily  necessary  to  determine  the  content  of  car- 
bonate of  lime  and  phosphoric  acid,  and  of  the  injurious 


GENERAL   RULES   FOR  SOIL-ANALYSIS.  169 

ones,  the   presence  of  ferrous  sulphate,  free  sulphuric 
acid,  and  iron  disulphide. 

5.  In  all  chemical  and  physical  examinations  of  the 
top-soil,  fine  soil  less  than  2  millimeters  in  diameter, 
dried  at  212°  F.,  is  to  be  used,  and  the  results  must  be 
referred  to  it. 

6.  In  regard  to  the  separation  of  the  soil-constituents, 
the  content  of  lime,  clay,  humus,  and  sand  in  the  fine 
soil  of  the  top-soil,  dried  at  212°  F.,  is  to  be  determined. 

7.  Exclusive   of   moor-soils,    the    determination    of 
nitrogen  is  only  to  be  executed  with  top-soils. 

8.  For  the   determination   of  the   plant-nourishing 
substances  the  extraction  with  boiling  concentrated  sul- 
phuric acid  is  preferably  to  be  used,  and,  as  a  rule,  only 
the  top-soil  (fine  soil  less  than  2  millimeters  in  diameter) 
need   to   be   considered.     In    making  the   experiment, 
calcareous  earth,  magnesia,  potash,  phosphoric  acid,  and 
sulphuric  acid  must  first  of  all  be  determined.     How- 
ever, the  substances  not  belonging  to  the  actual  plant- 
nourishing  substances,  such   as   silica,  alumina,    ferric 
oxide,  oxide  of  manganese,  and  sodium  must  also  be 
taken  into  consideration. 

9.  For  the    determination   of    Knop's    absorption- 
coefficient,  air-dry  fine  earth  less  than  0.5  millimeter  in 
diameter  is  to  be  used.     The  experiments  can  only  be 
executed  with  top-soils,  for  the  judging  of  which  they 
are  of  great  importance. 

10.  Of  the  physical  examinations  the  water  capacity 
(if  possible  in  the  open  field)  and  the  capillary  attraction 
are  chiefly  to  be  considered. 


INDEX. 


A  BSORBENT  power  of  the  soil, 
A     testing  the,  147-149 
Absorption-coefficient,     definition 

of,  148,  149 
determination  of  the,  149 

-151 

Acid, carbonic, determination  of, by 
direct  weigh- 
ing, 64-67 
of  the,  by  weigh- 
ing  from  the 
loss,  65-64 
volumetric    measurement 

of  the,  56-61 
fluoric,    disintegration    with, 

100.  101 

free  sulphuric, ferrous  sulphate 
and  iron  disulphide,  deter- 
mination of  the,  140-144 
hydrochloric,  extraction  of  the 

'soil  with,  130-133 
nitric,  determination  of,  110- 

123 
phosphoric,  absorption  of,  147, 

148 

Finkener's  method  of  de- 
termining, 127-129 
precipitation  of  the,  with 
ammonium  molybdate, 
126,  127 
sulphuric,   determination    of, 

109,  110 

disintegration  with,  83-87 
Acids,  determination  of  the,  in  the 
aqueous    extract,    108- 
123 

free  humic,  proof  of  the 
presence  of,  in  the  soil, 
139,  140 
Adhesion  and  cohesion  of  the  soil, 

16(5,  167 

Alkali  soils,  taking  specimens  of, 
29 


Alluvium,  formation  of,  20 
Alumina,  separation  of  the  ferric 

oxide,  from  the,  87-94 
Ammonia,  determination  of  the,  in 

the  soil,  137-139 

Ammon,  G.,  summary  of  his  ex- 
periments, 161,  16'_>" 
Ammonium  chloride,  determina- 
tion of,  117,  118 
molybdate,  precipitation  of  the 
phosphoric  acid  with,  126, 
127 

nitrate,  determination  of  the 
carbonate  of  calcium  and 
magnesium, by  boiling  with, 
67-72 

phospho-molybdate,    determi- 
nation   of    the    phosphoric 
acid  as,  127-129 
Analyses,  scheme  of  a  table  for,  45, 

46 

Analysis,  elementary,  determina- 
tion of  the  carbon  of  the 
humus  substances,  by,  78- 
81 

silt,  34-55 

Aqueous  extract,  determination  of 

the  acids  in 

the,  108-123 

of  the  bases  in 

the,  103-108 

vapor,  absorbent  capacity  of 

the  soil  for,  159,  160 
table  for  finding  the  ten- 
sion of,  116 


BASES,  determination  of  the,  in 
the  aqueous  extract,  103-108 
Behavior  of  the  soil  towards  water, 

151-159 

Bennigsen's  elutriating  flask,  34 
Blast  lamp,  71 


172 


INDEX. 


Boiling  flask,  Erlenraeyer,  131 
Bremen,  methods  used  in  the  Prus- 
sian moor  experimental  station 
at,  140-143 

Bromine,  disintegration  with,  143, 
144 


/CALCIUM  and  magnesium,  car- 
Ij        bonate  of,  determination  of, 

67-72 

carbonate  or  magnesium  car- 
bonate, determination  of  the 
content  of,  56-72 
Capillary  attraction  of  the  soil,  158, 

159 
Carbon,  absorption  of  by  the  plant, 

24 
Carbon  of  the  humus  substances, 

determination  of  the,  78-81 
Carbonate,  calcium  or  magnesium, 
determination  of  the  content 
of,  56-72 
of  calcium   and   magnesium, 

determination  of,  67-72 
sodium,  disintegration    with, 

99,  100 

Carbonic  acid,  determination  of,  by 
direct  weigh- 
ing, 64-67 
of  the, by  weigh- 
ing, from  the 
loss,  62-64 

Finkener's  table  for  cal- 
culating, 59-61 
volumetric    measurement 

of  the,  56-61 
Chlorine,   determination   of,   108, 

109 

Classification  of  soils,  21-23 
Clav,  calculation  of  the  content  of, 

in  the  total  soil,  92-94 
determination  of  the  content 

of,  82-94 

importance  of,  as  a  soil-con- 
stituent, 22,  23 
soils,  21 
Cohesion  and  adhesion  of  the  soil, 

166, 167 
Combustion  furnace,  79 


TYENUDATION  of  the  soil,  19,  20 

\J     Derivation  and  formation  of 

the  soil,  17-20 


Determination  of  the  plant-nour- 
ishing substances,  101-139 
of  the  soil -constituents,  56-101 
of  the  substances  in  the  soil 
injurious  to  the  growth   of 
plants,  139-144 
of  various  properties  of  the 

soil,  144-167 
Dietrich's  table  for  the  absorption 

of  nitrogen,  122 
Drying  stand,  Finkener's,  128 
"  stove,  70,  73-75 


FARTH,  fine,  33 

Jj    superficial    formation   of   the 

crust  of  the,  17 

Elementary    composition    of    the 
soil,  determination  of  the,  99- 
101 
Elements  found  in  plants,  26 

to  be  considered  in  soil-analy- 
sis, 26 

Elutriating  apparatus,  52-55 
Hilgard's,  52-55 
Noebel's,  34-36 
Schoene's,  36-52 
cylinder,  Kuehn's,  34 
process,  precautions  to  be  ob- 
served in  the,  54,  55 
products  obtained  by  the, 

50,51 

space,  cylindrical,  determina- 
tion of  the  diameter  of  the, 
40 

velocities,  products  of  granu- 
lation corresponding  to,  44 
velocity,  formulas   for  calcu- 
lating the,  41-44 

Elutriation  and  granulation,  cal- 
culating and   entering    the 
products  of,  51.  52 
definition  of  velocity  of,  36 
products    of,    obtained    with 

Noebel's  apparatus,  36 
with  distilled  water,  apparatus 

for,  47-52 

Elutriator,  Schoene's,  37,  38 
Erlenmeyer  boiling  flask,  131 
Evaporating  power  of  the  soil,  156, 
157 


T1ERRIC  oxide,  separation  of  the, 
D     from  the  alumina,  87-94 


INDEX. 


173 


Ferrous  oxide,   determination    of 

the  iron  as,  87-90 
sulphate,  free  sulphuric  acid 
and  iron  disulphide,  deter- 
mination of  the,  140-144 
Fesca,  definition  of  fine  soil  by,  33 
Filters,  weighed,  preparation   of, 

106 
Filtrating  power  of  the  soil,  157, 

158 
Fine  earth,  33 

soil,  33 

Finkener's  apparatus,  64-67 
drying  stand,  128 
method  of  determining  phos- 
phoric acid,  127-129 
tables  for  calculating  the  car- 
bonic acid,  59-61 
Fluids,  specifically  heavy,  96 
Fluoric  acid,  disintegration  with, 

100,  101 

Forchhammer's  theory  of  the  form- 
ation of  kaolin,  19 
Formation  and  derivation  of  the 

soil,  17-20 

Formulas  for  calculating  the  elu- 
triating velocity,  41-44 
Funnel,  hot  water,  68 
Furnace,  combustion,  79 
tubular,  84 


nASES,  behavior  of  the  soil  to- 

\J     wards,  159-163 

Gein,  72 

Geissler  potash  apparatus,  65 

General  rules  for  soil-analysis,  167- 
169 

Goldschmidt's  specifically  heavy 
fluid,  95 

Granulating  with  the  sieve,  31-34 

Granulation  and  elutriation,  cal- 
culating and  entering  the  pro- 
ducts of,  51,  52 


HAZARD'S  method  of  determi- 
ning the  content  of   quartz, 
96-99 
Heat- absorbent  power  of  the  soil, 

163-165 
Heat,  behavior  of  the  soil  towards, 

163-166 

Heat-conducting  power  of  the  soil, 
165,  166 


Heavy  soils,  definition  of,  23 
Heinrich's  method  of  determining 
the    adhesion   of 
soils,  167 

of  determining  the 
coherence  of  the 
soil,  166, 167 
of  determining  the 
water  capacity  of 
the  soil  in  the 
open  field,  155, 
156 

of  testing  the  ven- 
tilating power  of 
the  soil,  162,  163 
Hilgard's    elutriating    appaiatus, 

52-55 

Hot-water  funnel,  68 
Humic  acids,  free,  proof  of  the 
presence  of,  in  the  soil,  139,  140 
Humus,  acid,  72 
definition  of,  72 
determination  of  the,  by  igni- 
tion, 81,  82 
neutral,  72 
soils,  21 
substances,  determination  of, 

72-82 

of  the  carbon 
of  the,  78- 
81 

Hydrochloric  acid,  extraction   of 
the  soil  with,  130-133 


TNORGANIC   combinations,  ele- 
J.         ments  for  the  formation  of, 

26 

substances  in  plants,  26 
Iron,  determination  of  the,  as  fer- 
rous oxide,  87-90 
disulphide,  ferrous   sulphate, 
and  free  sulphuric  acid,  de- 
termination of  the,  140-144 


T7AOLINIZATION,   process    of, 
JV    19 

Kjeldahl's  method  of  determining 

nitrogen,  133-135 
Knop,  definition  of  fine  earth  and 

fine  soil  by,  33 

Knop's  elutriating  cylinder,  34 
method  for  the  determination 
of  humus,  73-78 


174 


INDEX. 


Knop's  method  of  determining  the 
absorption-coefficient,  149-151 

Knop-Wagner  azotometer,  deter- 
mination of  the  nitrogen,  by  the, 
118-123 

Kuehn's  elutriating  cylinder,  34 


T  ABORATORT,  experiments  to 

JJ    determine  the  power  of  the 

soil  to  retain  moisture,  in  the, 

151-154 

Laufer's  method  of  obtaining  small 

grains,  45 
Liburnau,  Lorenz  von,  system  of 

soil  classification  of,  21 
Light  soils,  definition  of,  23 
Lime  soils,  21 
Loam  soils,  21 
Loams,  light  and  heavy,  23 


MAGNESIUM  carbonate  or  cal- 
cium carbonate,  determina- 
tion of  the  content  of,  56- 
72 

pyrophosphate,  weighing  the 
phosphoric  acid  as,  126,  127 
Marl  soils,  21 

Mayer's  method  of  determining 
the  power  of  the  soil  to  retain 
moisture,  154 

Mechanical  soil-analysis,  31-55 
Minerals  contained  in  rocks,  trans- 
formation of,  18,  19 
table  of  specific  gravities  of,  96 
Mohr's  apparatus,  62-64 
Monocalcium  phosphate,  prepara- 
tion of,  147,  148 

Muencke,  R.,  drying  chamber,  de- 
vised by,  70,  73-75 


NITRIC   acid,  determination  of, 
110-123 

Nitrogen,    determination   of   the, 
by  combustion  with 
soda-lime,  135-137 
of  the,  by  the  Kuop- 
Wagner     azotome- 
ter, 118-123 
of  the  total,  in    the 

soil,  133-137 

Dietrich's  table  for  the  absorp- 
tion of,  122 


Nitrogen,  KjeldahPs  method  of  de- 
termining, 133-135 

Noebel's  elutriating  apparatus,  34- 
36 

Normal  solutions,  preparation  of, 
147 

Nourishing  substances,  behavior 
of  the  soil  towards,  146-151 


OBJECT    of    soil-analysis,    24- 
27 
Organic  combinations,  elements  for 

the  formation  of,  26 
in  plants,  25,  26 
Orth's  auxiliary  cylinder,  45 
Oxide,   ferric,  separation  of   the, 

from  the  alumina,  87-94 
Oxygen,  absorbent  power  of  the 
soil  for,  160, 161 


PEAT,  definition  of,  72 
special  method  in  the  exami- 
nation of,  123 

Phosphate  monocalcium,  prepara- 
tion of,  147,  148 
Phosphoric   acid,    absorption    of, 

147,  148 

determination  of 
the,  as  ammo- 
nium phospho- 
molybdate,  127- 
129 

Finkener's  method 
of  determining, 
127-129 

precipitation       of 
the,  with  ammo- 
nium molybdate, 
126,  127 
Plant,  absorption  of  carbon  by  the, 

24 
elementary  substances  of  the, 

25,  26 

Plant-nourishing  substances,   de- 
termination of  the,  101-139 
Plants,  content  of  water  in,  25 
determination  of  some  import- 
ant substances  for  the 
nourishment  of,  133-139 
of  the  substances  in  the 
soil    injurious    to    the 
growth  of,  139-144 
elements  found  in,  26 


INDEX. 


175 


Plants,  inorganic  substances  in, 26 
organic  combinations  in,  25, 26 
Porosity  of  the  soil,  145  ,14(5 
Potash  apparatus,  Geissler,  65 
Potassium  permanganate  solution,  ' 
determination  ofj 
the  iron  by  titra- 
tion  with,  87-90 
solution,  standard- 
izing of  the,  90- 
93 

Preparatory  labors  for  soil-analy- 
sis, 28-31 

Prussian  moor  experimental  sta- 
tion at  Bremen,  methods  used 
in  the,  140-143 


QUARTZ,  determination  of  the 
content  of,  96-99 


ROCKS,  disintegration  of,  17,  18 
Rohrbach's  specifically  heavy 

fluid,  96 

Rules,  general    for    soil-analysis, 
167-169 


SALT,  common,  determination  of 
content  of,  in  the  soil,  140 
Salts  suitable  for  testing  the  ab- 
sorbent power  of  the  soil,  147 
Salty  soils,  taking  specimens  of,  29 
Sand,  determination   of  the  con- 
tent of,  94-96 

petrographic  determination  of 
the  coarser  admixed  parts 
of,  94-96 
soils,  21 

Scheibler's  apparatus  for  the  volu- 
metric measurement  of  carbonic 
acid,  57 

Schloesing's  method  for  the  deter- 
mination of  the  ammonia  in  the 
soil,  138,  139 

Schloesing  -  Schulze's        modified 
method   for    the  determination 
of  nitric  acid,  111-116 
Schoene  and  Wolff,  E.,  definition 

of  fine  earth  by,  33 
Schoene's   elutriating    apparatus. 

36-52 

Sieve,  granulating  with  the,  31-34 
Silt-analysis,  34-55 


Soda-lime,   determination  of   the 
nitrogen    by  combustion   with, 
135-137 
Sodium  carbonate,  disintegration 

with,  99,  100 

Soil,  absorbent  capacity  of  the,  for 

aqueous  vapor,  159,  160 

power  of  the,  for  oxygen, 

160, 161 

Soil-analysis,  execution  of  a  com- 
plete, 27 

general  rules  for,  167-169 
mechanical,  31-55 
object  of,  24-27 
preparatory  labors  for,  28-31 
Soil,  behavior  of,  towards  gases, 

159-163 
of  the,  towards  heat,  163- 

166 
of  the,  towards  nourishing 

substances,  146-151 
of  the,  towards  water,151- 

159 
calculation  of  the  content  of 

clay  in  the  total,  92-94 
capillary  attraction  of  the,  158, 

159 

characterization    of   the    me- 
chanical composition  of  a,  32 
coherence  and    adherence  of 

the,  166,  167 
Soil-constituents,  determination  of 

the,  56-101 

Soil,  denudation  of  the,  19,  20 
derivation  and  formation  of, 

17-20 
determination  of  the  ammonia 

in  the,  137-139 
of  the  content  of  common 

salt  in  the,  140 
of  the  elementary  compo- 
sition of  the,  99-101 
of  the  full  capacity  of  the, 

for  water,  152 
of  the  specific  gravity  of 

the,  144,  145 

of  the  substances  in  the, 
injurious  to  the  growth 
of  plants,  139-144 
of  the  sulphur  in  the,  141- 

145 
of  the  total  nitrogen  in 

the,  133-137 

of  the  volume  weight  of 
the,  145, 146 


176 


INDEX. 


Soil,  determination  of  the  water 
capacity  of  the,  in   the 
open  field,  154-156 
of  various  properties    of 

the,  144-167 
drying  and  storing  samples  of, 

31 
evaporating  power  of  the,  156, 

157 

extraction   of  the,  with  car- 
bonated water,  123-130 
of  the,  with  cold,  distilled 

water,  102-123 
of  the,  with  hydrochloric 

acid,  130-133 

Soil-extractions,  determination  of 
plant-nourishing  substances  in, 
102-133 
Soil,  filtrating  power  of  the,  157, 

158 

fine,  33 
forces  active  in  the  formation 

of  the,  17 

further  treatment  of  the,  ex- 
tracted    with      carbonated 
water,  129, 130 
granulation    of   the,    by    the 

sieve,  31-34 
greatest  or  full  capacity  of  the, 

for  water,  152 
heat-absorbent!  power  of  the, 

163-165 
heat-conducting  power  of  the, 

165, 166 
points  to  be  noted  regarding 

the,  30 

porosity  of  the,  145, 146 
proof  of  the  presence  of  free 
humic  acids  in  the,  139,  140 
testing  the  absorbent  power  of 

the,  147-149 
the  apparent  specific  gravity 

of  the,  145 
transportation    of,   by  water, 

19,  20 
value  of  the,  for  cultivation, 

22 
ventilating  power  of  the,  162, 

163 

weight  of  the,  144-166 
Soils,  classification  of,  21-23 
clay,  21 

definition  of  light  and  heavy,  23 
deposited  or  transported,  21 
derived,  21 


Soils,  humus,  21 
lime,  21 
loam,  21 
marl,  21 

primitive  or  original,  2L 
sand,  21 
stony,  21 
sub,  23 

taking  specimens  of,  28-30 
top,  23 
true,  23 

Specific  gravity  of  the  soil,  deter- 
mination   of     the, 
144, 145 
the  apparent,  of  the 

soil,  145 
Stony  soils,  21 

Sub-soil,  importance  of  the  exami- 
nation of  the,  168,  169 
Sub-soils,  23 

Sulphate,  ferrous,  free  sulphuric 
acid  and  iron  disulphide,  deter- 
mination of  the,  140-144 
Sulphur,  determination  of  the,  in 

the  soil,  141-145 
Sulphuric  acid,  determination  of, 

109,  110 
disintegration     with, 

83-87 

free,  ferrous  sulphate 
and  iron  disulphide, 
determination  of 
the,  140-144 


TIABLE,   Dietrich's,  for  the  ab- 
sorption of  nitrogen,  122 
for  analyses,  scheme  of  a,  45, 

46 
Finkener's,    for     calculating 

carbonic  acid,  59-61 
Thaer,   Albrecht,   system  of   soil 

classification  proposed  by,  21 
Thoulet's  specifically  heavy  fluid, 

95 

Tiemaun's  method  for  the  deter- 
mination of  nitric  acid,  111-116 
Top  soils,  23 
True  soils,  23 
Tubular  furnace,  84 


T7ELOCITIES,  elutriating,  pro- 
V    ducts  of  granulation    corres- 
ponding to,  44 


INDEX. 


177 


Velocity,  elutriating,  formulas  for 
calculating  the,  41-44 

Ventilating  power  of  the  soil,  162, 
163 

Volume  weight  of  the  soil,  deter- 
mination of,  145, 146 


WATER-BATH,  covered,  106 
Water,  behavior  of  the  soil 

towards,  151-159 

Water  capacity  of  the  soil,  deter- 
mination of  the,  in  the  open 
field,  154-156 
carbonated,  extraction  of  the 

soil  with,  123-130 
cold  distilled,  extraction  of  the 

soil  with,  102-123 
content  of,  in  plants,  25 


j  Water,  determination  of  the  full 

capacity  of  the  soil  for,  152 

distilled,  apparatus  for  elutri- 

ation  with,  47-52 
greatest  or  full  capacity  of  the 

soil  for,  152 
transportation  of  soil,  by,  19, 

20 

Weathering,  17 
Weight  of  the  soil,  144-146 
Wolf's,  W.,  method  of  determining 

the  nitric  acid,  116-118 
Wolff,  E.,  and  Schoene,  definition 

of  fine  earth  by,  33 
Wolff's,  E.,  method  for  determin- 
ing the  evaporating  power  of  the 
soil,  156,  157 

Wollny's  deductions  from  his  ex- 
periments on  the  heat-conduct- 
ing power  of  the  soil,  165,  166 


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By  W.  BEMROSE,  JR.  i  vol.  quarto  ....  $3.00 

BEMROSE.— Manual  of  Wood  Carving: 

With  Practical  Illustrations  for  Learners  of  the  Art,  ?,nd  Original  and 
Selected  Designs.  By  WILLIAM  BEMROSE,  JR.  With  an  Intro- 
duction by  LLEWELLYN  JEWITT,  F.  S.  A.,  etc.  With  128  illustra- 
tions, 4to. $2.50 

BILLINGS.— Tobacco : 

Its  History,  Variety,  Culture,  Manufacture,  Commerce,  and  Various 
Modes  of  Use.  By  E.  R.  BILLINGS.  Illustrated  by  nearly  200 
engravings.  8vo $3-oC 

3IRD. — Tbe  American  Practical  Dyers'  Companion: 
Comprising  a  Description  of  the  Principal  Dye-Stuffs  and  Chemicals 
used  in  Dyeing,  their  Natures  and  Uses ;  Mordants,  and  How  Made ; 
with  the  best  American,  English,  French  and  German  processes  for 
Bleaching  and  Dyeing  Silk,  Wool,  Cotton,  Linen,  Flannel,  Felt, 
Dress  Goods,  Mixed  and  Hosiery  Yarns,  Feathers,  Grass,  Felt,  Fur, 
Wool,  and  Straw  Hats,  Jute  Yarn,  Vegetable '  Ivory,  Mats,  Skins, 
Furs,  Leather,  etc.,  etc.  By  Wood,  Aniline,  and  other  Processes, 
together  with  Remarks  on  Finishing  Agents,  and  Instructions  in  the 
Finishing  of  Fabrics,  Substitutes  for  Indigo,  Water-Proofing  of 
Materials,  Tests  and  Purification  of  Water,  Manufacture  of  Aniline 
and  other  New  Dy<-  Wares,  Harmonizing  Colors,  etc.,  etc. ;  embrac- 
ing in  all  over  800  Receipts  for  Colors  and  Shades,  accompanied  by 
170  Dyed  Samples  of  Ra-v  Materials  and  Fabrics.  By  F.  J.  BIRD, 
Practical  Dyer,  Author  of  "The  Dyers'  Hand-Book."  8vo.  $10.00 

BLINN. — A  Practical  Workshop  Companion  for  Tin,  Sheet* 

Iron,  and  Copper-plate  Workers  : 

Containing  Rules  for  describing  various  kinds  of  Patterns  used  by 
Tin,  Sheet-Iron  and  Copper-plate  Workers;  Practical  Geometry; 
Mensuration  of  Surfaces  and  Solids ;  Tables  of  the  Weights  of 
Metals,  Lead-pipe,  etc. ;  Tables  of  Areas  and  Circumference* 
of  Circles;  Japan,  Varnishes,  Lackers,  Cements,  Comprsjtions,  etc., 
etc.  By  LEROY  J.  BLINN,  Master  Mechanic.  With  One  Hundred 
.and  Seventy  Illustrations.  I2mo $3.50 


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BOOTH. — Marble  Worker's  Manual: 

Containing  Practical  Information  respecting  Marbles  in  general,  theil 
Cutting,  Working  and  Polishing ;  Veneering  of  Marble ;  Mosaics ; 
Composition  and  Use  of  Artificial  Marble,  Stuccos,  Cements,  Receipts, 
Secrets,  etc.,  etc.  Translated  from  the  French  by  M.  L.  BOOTH. 
With  an  Appendix  concerning  American  Marbles.  I2mo.,  cloth  £1.50 

BOOTH    and    MORFIT. — The    Encyclopaedia   of    Chemistry, 

Practical  and  Theoretical : 

Embracing  its  application  to  the  Arts,  Metallurgy,  Mineralogy, 
Geology,  Medicine  and  Pharmacy.  By  JAMES  C.  BOOTH,  Melter 
and  Refiner  in  the  United  States  Mint,  Professor  of  Applied  Chem- 
istry in  the  Franklin  Institute,  etc.,  assisted  by  CAMPBELL  MORFIT, 
author  of  "  Chemical  Manipulations,"  etc.  Seventh  Edition.  Com- 
plete in  one  volume,  royal  8vo.,  978  pages,  with  numerous  wood-cuts 
and  other  illustrations $3-5° 

BRAM WELL.— The  Wool  Carder's  Vade-Mecum. 

A  Complete  Manual  of  the  Art  of  Carding  Textile  Fabrics.  By  W, 
C.  BRAMWELL.  Third  Edition,  revised  and  enlarged.  Illustrated. 
Pp.  400.  I2mo $2.50 

BRANNT. — A    Practical   Treatise  on  Animal  and  Vegetable 

Fats  and  Oils : 

Comprising  both  Fixed  and  Volatile  Oils,  their  Physical  and  Chemi- 
cal Properties  and  Uses,  the  Manner  of  Extracting  and  Refining 
them,  and  Practical  Rules  for  Testing  them ;  as  well  as  the  Manu- 
facture of  Artificial  Butter,  Lubricants,  including  Mineral  Lubricating 
Oils,  etc.,  and  on  Ozokerite.  Edited  chiefly  from  the  German  oi 
DRS.  KARL  SCHAEDLER,  G.  W.  ASKINSON,  and  RICHARD  BRUNNER, 
with  Additions  and  Lists  of  American  Patents  relating  to  the  Extrac- 
tion, Rendering,  Refining,  Decomposing,  and  Bleaching  of  Fats  and 
Oils.  By  WILLIAM  T.  BRANNT.  Illustrated  by  244  engravings. 
739  pages.  8vo $12.50 

BRANNT.— A  Practical  Treatise  on  the  Manufacture  of  Soap 

and  Candles : 

Based  upon  the  most  Recent  Experiences  in  the  Practice  and  Science ; 
comprising  the  Chemistry,  Raw  Materials,  Machinery,  and  Utensils 
and  Various  Processes  of  Manufacture,  including  a  great  variety  of 
formulas.  Edited  chiefly  from  the  German  of  Dr.  C.  Deite,  A. 
Engelhardt,  Dr.  C.  Schaedler  and  others;  with  additions  and  lists 
of  American  Patents  relating  to  these  subjects.  By  WM.  T.  BRANNT. 
Illustrated  by  163  engravings.  677  pages.  8vo.  .  .  $7.50 

BRANNT. — A  Practical  Treatise  on  the  Raw  Materials  and  the 
Distillation  and  Rectification  of  Alcohol,  and  the  Prepara- 
tion of  Alcoholic  Liquors,  Liqueurs,  Cordials,  Bitters,  etc.: 
Edited  chiefly  from  the  German  of  Dr.  K.  Stammer,  Ilr.  F.  Eisner, 
and  E.  Schubert.     By  WM.  T.  BRANNT.     Illustrated  by  thirty-one 
engravings.      121110.  ..,..„.          $2.50 


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BRANNT— WAHL.— The  Techno- Chemical  Receipt  Book: 

Containing  several  thousand  Receipts  covering  the  latest,  most  «ra 
portant,  and  most  useful  discoveries  in  Chemical  Technology,  ano 
their  Practical  Application  in  the  Arts  and  the  Industries.  Edited 
chiefly  from  the  German  of  Drs.  Winckler,  Eisner,  Heintze,  Mier- 
zinski,  Jacobsen,  Koller,  and  Heinzerling,  with  additions  by  WM.  1. 
BRANNT  and  WM.  H.  WAHL,  PH.  D.  Illustrated  by  78  engravings, 
ismo.  495  pages  .  .  .  §2.00 

BROWN. — Five  Hundred  and  Seven  Mechanical  Movements: 
Embracing  all  those  which  are  most  important  in  Dynamics,  Hy- 
draulics, Hydrostatics,  Pneumatics,  Steam-Engines,  Mill  and  other 
Gearing,  Presses,  Horology  and  Miscellaneous  Machinery ;  and  in- 
cluding many  movements  never  before  published,  and  several  of 
which  have  only  recently  come  into  use.  By  HENRY  T.  BROWN, 
I2mo.  ..........  gi.oo 

BUCKMASTER. — The  Elements  of  Mechanical  Physics  : 
By  J.  C.   BUCKMASTER.       Illustrated   with   numerous   engravings. 
I2mo. $l.oo 

BULLOCK. — The  American  Cottage  Builder  : 
A  Series  of  Designs,  Plans  and  Specifications,  from  $200  to  $20,000, 
for  Homes  for  the  People ;  together  with  Warming,  Ventilation, 
Drainage,  Painting  and  Landscape  Gardening.  By  JOHN  BULLOCK, 
Architect  and  Editor  of  "  The  Rudiments  of  Architecture  and 
Building,"  etc.,  etc.  Illustrated  by  75  engravings.  8vo.  $3.00 

BULLOCK. — The  Rudiments  of  Architecture  and  Building : 
For  the  use  of  Architects,  Builders,  Draughtsmen,  Machinists,  En- 
gineers and  Mechanics.     Edited  by  JOHN  BULLOCK,  author  of  "  The 
American  Cottage  Builder."   Illustrated  by  250  Engravings.  8vo.  $3.00 

BURGH. — Practical    Rules    for    the   Proportions   of     Modern 

Engines  and  Boilers  for  Land  and  Marine  Purposes. 
By  N.  P.  BURGH,  Engineer.     I2mo.  ....         $1.50 

BYLES.— Sophisms    of    Free    Trade    and    Popular    Political 

Economy  Examined. 

By  a  BARRISTER  (SIR  JOHN  BARNARD  BYLES,  Judge  of  Common 
Pleas).  From  the  Ninth  English  Edition,  as  published  by  ihe 
Manchester  Reciprocity  Association.  iamo.  .  .  .  $1.25 

BOWMAN.— The  Structure  of  the  Wool  Fibre  in  its  Relation 

to  the  Use  of  Wool  for  Technical  Purposes : 
Being  the  substance,  with  additions,  of  Five  Lectures,  delivered  at 
the  request  of  the  Council,  to  the  members  of  the  Bradford  Technical 
College,  and  the  Society  of  Dyers  and  Coloiists.  Bv  F.  H.  BOW- 
MAN, D.  Sc.,  F.  R.  S.  E.,  F.  L.  S.  Illustrated  by  32  engravings. 
8vo. $6.50 

BYRNE. — Hand-Book  for  the  Artisan,  Mechanic,  and  Engi- 
neer : 

Comprising  the  Grinding  and  Sharpening  of  Culling  Tools,  Abir.-.  ve 
Processes,  Lapidary  Work,  Gem  and  Glass  Engraving,  Varnishing 
and  Lackerinsj,  Apparatus,  Materials  and  Processes  for  Grinding  and 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


Polishing,  etc.  By  OLIVER  BYRNE.  Illustrated  by  185  wood  en- 
gravings. 8vo.  ........  $5.00 

BYRNE.— Pocket-Book  for  Railroad  and  Civil  Engineers: 
Containing  New,  Exact  and  Concise  Methods  for  Laying  out  RailroaA 
Curves,  Switches,  Frog  Angles  and  Crossings;  the  Staking  out  of 
work;  Levelling;  the  Calculation  of  Cuttings;  Embankments;  Earth- 
work, etc.  By  OLIVER  BYRNE.  i8mo.,  full  bound,  pocket-book 
form $!-7S 

BYRNE.— Tne  Practical  Metal- Worker's  Assistant :  f 

Comprising  Metallurgic  Chemistry;  the  Arts  of  Working  all  Metals 
and  Alloys  ;  Forging  of  Iron  and  Steel ;  Hardening  and  Tempering; 
Melting  and  Mixing;  Casting  and  Founding  ;  Works  in  Sheet  Metal; 
the  Processes  Dependent  on  the  Ductility  of  the  Metals;  Soldering; 
and  the  most  Improved  Processes  and  Tools  employed  by  Metal- 
Workers.  With  the  Application  of  the  Art  of  Electro-Metallurgy  to 
Manufacturing  Processes;  collected  from  Original  Sources,  and  from 
the  works  of  Holtzapffel,  Bergeron,  Leupold,  Plumier,  Napier, 
Scoffern,  Clay,  Fairbairn  and  others.  By  OLIVER  BYRNE.  A  new, 
revised  and  improved  edition,  to  which  is  added  an  Appendix,  con- 
taining The  Manufacture  of  Russian  Sheet-Iron.  By  JOHN  PERCY, 
M.  D.,  F.  R.  S.  The  Manufacture  of  Malleable  Iron  Castings,  and 
Improvements  in  Bessemer  Steel.  By  A.  A.  FESQUET,  Chemist  and 
Engineer.  With  over  Six  Hundred  Engravings,  Illustrating  every 
Branch  of  the  Subject.  8vo $5.00 

BYRNE.— The  Practical  Model  Calculator: 

For  the  Engineer,  Mechanic,  Manufacturer  of  Engine  Work,  Navai 
Architect,  Miner  and  Millwright.  By  OLIVER  BYRNE.  8vo.,  nearly 
600  pa^es $3  oo 

CABINET  MAKER'S  ALBUM  OF  FURNITURE; 

Comprising  a  Collection  of  Designs  for  various  Styles  of  Furniture. 
Illustrated  by  Forty-eight  Large  and  Beautifully  Engraved  Plates. 
Oblong,  8vo $2.00 

CALLINGHAM.— Sign  Writing  i:nd  Glass  Embossing: 

A  Complete  Practical  Illustrated  "Manual  of  the  Art.  By  JAMES 
CALLINGHAM.  lamo $1.50 

CAMPIN. — A  Practical  Treatise  on  Mechanical  Engineering: 
Comprising  Metallurgy,  Moulding,  Casting,  Forging,  Tools,  Work- 
shop Machinery,  Mechanical  Manipulation,  Manufacture  of  Steam- 
Engines,  etc.  With  an  Appendix  on  the  Analysis  of  Iron  and  Iron 
Ores.  By  FRANCIS  CAMPIN,  C.  E.  To  which  are  added,  Observations 
on  the  Construction  of  Steam  Boilers,  and  Remarks  upon  Furnaces 
used  for  Smoke  Prevention ;  with  a  Chapter  on  Explosions.  By  R. 
ARMSTRONG,  C.  E.,  and  JOHN  BOURNE.  Rules  for  Calculating  th« 
Change  Wheels  for  Screws  on  a  Turning  Lathe,  and  for  a  Wheel* 
cutting  Machine.  By  J.  LA  NICCA.  Management  of  Steel,  Includ- 
ing Forging,  Hardening,  Tempering,  Annealing,  Shrinking  and 
Expansion ;  and  the  Case-hardening  of  Iron.  By  G.  EOF.  8vo. 
Ulustrated  with  twenty-nine  plates  and  100  wood  engravings  $5.00 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


CAREY.— A  Memoir  of  Henry  C.  Carey. 
By  DR.  WM.  ELDER.    With  a  portrait.     8vo.,  cloth        .        .        75 

CAREY.— The  Works  of  Henry  C.  Carey : 

Harmony  of  Interests  :   Agricultural,  Manufacturing  and  Commer- 
cial.    Svo.  ...    $1.25 

Manual  of  Social  Science.  Condensed  from  Carey's  "  Principles 
of  Social  Science."  By  KATE  McKEAN.  I  vol.  lamo.  .  $2.00- 
Miscellaneous  Works.  With  a  Portrait.  2  vols.  Svo.  $10.00 

Past,  Present  and  Future.     Svo $2.50 

Principles  of  Social  Science.  3  volumes,  Svo.  .  .  $7.50 
The  Slave-Trade,  Domestic  and  Foreign;  Why  it  Exists,  and 
How  it  may  be  Extinguished  (1853).  Svo.  .  .  .  $2.oo> 
The  Unity  of  Law :  As  Exhibited  in  the  Relations  of  Physical,. 
Social,  Mental  and  Moral  Science  (1872).  Svo.  .  .  $2.50. 

CLARK. — Tramways,  their  Construction  and  Working: 

Embracing  a  Comprehensive  History  of  the  System.  With  an  ex- 
haustive analysis  of  the  various  modes  of  traction,  including  horse- 
power, steam,  heated  water  and  compressed  air ;  a  description  of  thr 
varieties  of  Rolling  stock,  and  ample  details  of  cost  and  working  ex- 
penses.  By  D.  KINNEAR  CLARK.  Illustrated  by  over  200  wood 
engravings,  and  thirteen  folding  plates.  I  vol.  Svo.  .  $9.00' 

COLBURN.— The  Locomotive  Engine: 

Including  a  Description  of  its  Structure,  Rules  for  Estimating  its- 
Capabilities,  and  Practical  Observations  on  its  Construction  and  Man- 
agement. By  ZER AH  COLBURN.  Illustrated.  i2mo.  .  $1.00 

COLLENS. — The  Eden  of  Labor;  or,  the  Christian  Utopia. 
By  T.  WHARTON  COLLENS,  author, of  "  Humanics,"   "  The  History 
of  Charity,"  etc.     I2mo.     Paper  cover,  $1.00;  Cloth          .         $1.2$ 

COOLEY. — A  Complete  Practical  Treatise  on  Perfutnery: 
Being  a  Hand-book  of  Perfumes,  Cosmetics  and  other  Toilet  Articles. 
With   a  Comprehensive    Collection  of  Formulae.     By   ARNOLD  J. 
COOLEY.    I2mo $1.50 

COOPER.— A  Treatise  on  the  use  of  Belting  for  rtie  Trans- 
mission of  Power. 

With  numerous  illustrations  of  approved  and  actual  methods  of  ar- 
ranging Main  Driving  and  Quarter  Twist  Belts,  and  of  Belt  Fasten 
ings.  Examples  and  Rules  in  great  number  for  exhibiting  and  cal- 
culating the  size  and  driving  power  of  Belts.  Plain,  Particular  and 
Practical  Directions  for  the  Treatment,  Care  and  Management  or 
Belts.  Descriptions  of  many  varieties  of  Beltings,  together  witn. 
chapters  on  the  Transmission  of  Power  by  Ropes;  by  Iron  and 
Wood  Frictional  Gearing ;  on  the  Strength  of  Belting  Leather ;  and 
on  the  Experimental  Investigations  of  Morin,  Briggs,  and  others.  By 
JOHN  H.  COOPER,  M.  E.  Svo £3.50 

CRAIK. — The  Practical  American  Millwright  and  MUler. 

By  DAVID  CRAIK,  Millwright.  Illustrated  by  numerous  wood  en- 
gravings and  two  folding  plates.  Svo.  ....  $3.50 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.  9 

CROSS.— The  Cotton  Yarn  Spinner  : 

Showing  how  ihe  Preparation  should  be  arranged  for  Different 
Counts  of  Yarns  by  a  System  more  uniform  than  has  hitherto  been 
practiced;  by  having  a  Standard  Schedule  from  which  we  make  all 
our  Changes.  By  RICHARD  CROSS.  122  pp.  I2mo.  .  75 

CRISTIANI. — A  Technical  Treatise  on  Soap  and  Candles: 
With  a  Glance  at  the  Industry  of  Fats  and  Oils.     By  R.  S.  CRIS- 
TIANI, Chemist.     Author  of  "  Perfumery  and  Kindred  Arts."     Illus- 
trated by  176  engravings.     581  pages,  8 vo.         .         .         .     #15.00 

COAL  AND  METAL  MINERS'  POCKET  BOOK: 

Of  Principles,  Rules,  Formulae,  and  Tables,  Specially  Compiled 
and  Prepared  for  the  Convenient  Use  of  Mine  Officials,  Mining  En- 
gineers, and  Students  preparing  themselves  for  Certificates  of  Compe- 
tency as  Mine  Inspectors  or  Mine  Foremen.  Revised  and  Enlarged 
edition.  Illustrated,  565  pages,  small  I2mo.,  cloth.  .  $2.00 

Pocket  book  form,  flexible  leather  with  flap  .         .  $2.75 

DAVIDSON. — A  Practical  Manual  of  House  Painting,  Grain- 
ing, Marbling,  and  Sign- Writing: 

Containing  full  information  on  the  processes  of  House  Painting  in 
Oil  and  Distemper,  the  Formation  of  Letters  and  Practice  of  Sign- 
Writing,  the  Principles  of  Decorative  Art,  a  Course  of  Elementary 
Drawing  for  House  Painters,  Writers,  etc.,  and  a  Collection  of  Useful 
Receipts.  With  nine  colored  illustrations  of  Woods  and  Marbles, 
and  numerous  wood  engravings.  By  ELLIS  A,  DAVIDSON.  I2mo. 

#3-°° 
DAVIES.— A  Treatise  on  Earthy  and  Other    Minerals   and 

Mining: 

By  I).  C.  DAVIES,  F.  G.  S.,  Mining  Engineer,  etc.  Illustrated  by 
76  Engravings.  I2mo $5.00 

DAVIES. — A  Treatise  on  Metalliferous  Minerals  and  Mining: 
By  D.  C.  DAVIES,  F.  G.  S.,  Mining  Engineer,  Examiner  of  Mines, 
Quarries  and  Collieries.  Illustrated  by  148  engravings  of  Geological 
Formations,  Mining  Operations  and  Machinery,  drawn  from  the 
practice  of  all  parts  of  the  world.  Fifth  Edition,  thoroughly  Revised 
and  much  Enlarged  by  his  son,  E.  Henry  Davies.  I2mo.,  524 
pages  .......  .  $5.00- 

DAVIES.— A  Treatise  on  Slate  and  Slate  Quarrying: 

Scientific,  Practical  and  Commercial.  By  D.  C.  DAVIES,  F.  G.  S., 
Mining  Engineer,  etc.  With  numerous  illustrations  and  folding 
plates.  I2mo. $2.00 

DAVIS. — A  Practical  Treatise  on  the  Manufacture  of  Brick, 

Tiles  and  Terra-Cotta: 

Including  Stiff  Clay,  Dry  Clay,  Hand  Made,  Pressed  or  Front,  and 
Roadway  Paving  Brick,  Enamelled  Brick,  with  Glazes  and  Colors, 
Fire  Brick  and  Blocks,  Silica  Brick,  Carbon  Brick,  Glass  Pots,  Re- 


10          HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 

torts,  Architectural  Terra-Cotta,  Sewer  Pipe,  Drain  Tile,  Glazed  and 
Unglazed  Roofing  Tile,  Art  Tile,  Mosaics,  and  Imitation  of  Intarsia 
or  Inlaid  Surfaces.  Comprising  every  product  of  Clay  employed  in 
Architecture,  Engineering,  and  the  Blast  Furnace.  With  a  Detailed 
Description  of  the  Different  Clays  employed,  the  Most  Modern 
Machinery,  Tools,  and  Kilns  used,  and  the  Processes  for  Handling, 
Disintegrating,  Tempering,  and  Moulding  the  Clay  into  Shape,  Dry- 
ing, Setting,  and  Burning.  By  Charles  Thomas  Davis.  Third  Edi- 
tion. Revised  and  in  great  part  rewritten.  Illustrated  by  261 
engravings.  662  pages  .......  $5.00 

DAVIS. — A  Treatise  on  Steam-Boiler  Incrustation  and  Meth- 
ods for  Preventing  Corrosion  and  the  Formation  of  Scale: 
By  CHARLES  T.  DAVIS.     Illustrated  by  65  engravings.     8vo.    $1.50 

DAVIS. — The  Manufacture  of  Paper: 

Being  a  Description  of  the  various  Processes  for  the  Fabrication, 
Coloring  and  Finishing  of  every  kind  of  Paper,  Including  the  Dif- 
ferent Raw  Materials  and  the  Methods  for  Determining  their  Values, 
the  Tools,  Machines  and  Practical  Details  connected  with  an  intelli- 
gent and  a  profitable  prosecution  of  the  art,  with  special  reference  to 
the  best  American  Practice.  To  which  are  added  a  History  of  Pa- 
per, complete  Lists  of  Paper-Making  Materials,  List  of  American 
Machines,  Tools  and  Processes  used  in  treating  the  Raw  Materials, 
and  in  Making,  Coloring  and  Finishing  Paper.  By  CHARLES  T. 
DAVIS.  Illustrated  by  156  engravings.  608  pages,  8vo.  $6.00 

DAVIS. — The  Manufacture  of  Leather: 

Being  a  description  of  all  of  tt  Processes  for  the  Tanning,  Tawing, 
Currying,  Finishing  and  Dyeing  of  every  kind  of  Leather  ;  including 
the  various  Raw  Materials  and  the  Methods  for  Determining  their 
Values;  the  Tools,  Machines,  and  all  Details  of  Importance  con- 
nected with  an  Intelligent  ami  Profitable  Prosecution  of  the  Art,  with 
Special  Reference  to  the  Best  American  Practice.  To  which  are 
added  Complete  Lists  of  all  American  Patents  for  Materials,  Pro- 
cesses, Tools,  and  Machines  for  Tanning,  Currying,  etc.  By  CHARLES 
THOMAS  DAVIS.  Illustrated  by  302  engravings  and  12  Samples  of 
Dyed  Leathers.  One  vol.,  8vo.,  824  pages  .  .  .  $25.00 

DAWIDOWSKY— BRANNT.— A  Practical  Treatise  on  the 
Raw  Materials  and  Fabrication  of  Glue,  Gelatine,  Gelatine 
Veneers  and  Foils,  Isinglass,  Cements,  Pastes,  Mucilages, 
etc. : 

Eased  upon  Actual  Experience.  By  F.  DAWIDOWSKY,  Technical 
Chemist.  Translated  from  the  German,  with  extensive  additions, 
including  a  description  of  the  most  Recent  American  Processes,  by 
WILLIAM  T.  BRANNT,  Graduate  of  the  Royal  Agricultural  College 
of  Eldena,  Prussia.  35  Engravings.  I2mo.  .  .  .  $2.50 

DE  GRAFF. — The  Geometrical  Stair-Builders'  Guide : 

Being  a  Plain  Practical  System  of  Hand-Railing,  embracing  all  its 
necessary  Details,  and  Geometrically  Illustrated  by  twenty-two  Steel 
Engravings;  together  with  the  use  of  the  most  approved  principles 
f>{  Practical  Geometry.  By  SIMON  DE  GRAFF,  Architect  £to. 

$2.50 


HENRY   CAREY    BAIRD   &   CO.'S   CATALOGUE.        n 


DE  KONINCK— DIETZ.— A  Practical  Manual  of  Chemical 

Analysis  and  Assaying : 

As  applied  to  the  Manufacture  of  Iron  from  its  Ores,  and  to  Cast  Iron, 
Wrought  Iron,  and  Steel,  as  found  in  Commerce.  By  L.  L.  DB 
KONINCK,  Dr.  Sc.,  and  E.  DIETZ,  Engineer.  Edited  with  Notes,  by 
ROBERT  MALLET,  F.  R.  S.,  F.  S.  G.,  M.  I.  C.  E.,  etc.  American 
Edition,  Edited  with  Notes  and  an  Appendix  on  Iron  Ores,  by  A.  A. 
FESQUET,  Chemist  and  Engineer.  I2mo.  .  .  .  $1.50 

DUNCAN.— Practical  Surveyor's  Guide: 

Containing  the  necessary  information  to  make  any  person  of  corm 
mon  capacity,  a  finished  land  surveyor  without  the  aid  of  a  teacher 
By  ANDREW  DUNCAN.  Revised.  72  engravings,  214 pp.  I2mo.  $1.50 

DUPLAIS. — A  Treatise  on  the   Manufacture  and  Distillation 

of  Alcoholic  Liquors :  , 

Comprising  Accurate  and  Complete  Details  in  Regard  to  Alcohol 
from  Wine,  Molasses,  Beets,  Grain,  Rice,  Potatoes,  Sorghum,  Aspha 
del,  Fruits,  etc. ;  with  the  Distillation  and  Rectification  of  Brandy. 
Whiskey,  Rum,  Gin,  Swiss  Absinthe,  etc.,  the  Preparation  of  Aro- 
matic Waters,  Volatile  Oils  or  Essences,  Sugars,  Syrups,  Aromatic 
Tinctures,  Liqueurs,  Cordial  Wines,  Effervescing  Wines,  etc.,  the 
Ageing  of  Brandy  and  the  improvement  of  Spirits,  with  Copious 
Directions  and  Tables  for  Testing  and  Reducing  Spirituous  Liquors, 
etc.,  etc.  Translated  and  Edited  from  the  French  of  MM.  DUPI.AIS, 
Aine  et  Jeune.  By  M.  McKENNiE,  M.  D.  To  which  are  added  the 
United  States  Internal  Revenue  Regulations  for  the  Assessment  and 
Collection  of  Taxes  on  Distilled  Spirits.  Illustrated  by  fourteen 
folding  plates  and  several  wood  engravings.  743  pp.  8vo.  $1000 

DUSSAUCE.— Practical  Treatise  on  the  Fabrication  of  Matches, 

Gun  Cotton,  and  Fulminating  Powder. 
By  Professor  H.  DUSSAUCE.     I2mo.          .         .         .         .        $3  oo 

DYER  AND  COLOR-MAKER'S  COMPANION: 

Containing  upwards  of  two  hundred  Receipts  for  making  Colors,  on 
the  most  approved  principles,  for  all  the  various  styles  and  fabrics  now 
in  existence ;  with  the  Scouring  Process,  and  plain  Directions  for 
Preparing,  Washing-off,  and  Finishing  the  Goods.  I2mo.  $l.oo 

EDWARDS.— A  Catechism  of  the  Marine  Steam-Engine, 
For  the  use  of  Engineers,  Firemen,  and  Mechanics.  A  Practical 
Work  for  Practical  Men.  By  EMORY  EDWARDS,  Mechanical  Engi 
neer.  Illustrated  by  sixty-three  Engravings,  including  examples  i>( 
the  most  modern  Engines.  Third  edition,  thoroughly  revised,  with 
much  additional  matter.  I2mo.  414  pages  .  .  .  $2  oc 

EDWARDS. — Modern  American  Locomotive  Engines, 
Their  Design,  Construction  and  Management.     By  EMORY  EDWARDS* 
Illustrated  I2mo $2.00 

EDWARDS.— The  American  Steam  Engineer: 

Theoretical  and  Practical,  with  examples  of  the  latest  and  most  ap- 
proved American  practice  in  the  design  and  construction  of  Steam 
Engines  and  Boilers.  For  the  use  of  engineers,  machinists,  boiler- 
makers,  and  engineering  students.  By  EMORY  EDWARDS.  Fully 
illustrated,  419  pages.  i2mo.  «...  $2.50 


12         HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 

EDWARDS. — Modern  American  Marine  Engines,  Boilers,  ant 

Screw  Propellers, 

Their  Design  and  Construction.  Showing  the  Present  Practice  ot 
the  most  Eminent  Engineers  and  Marine  Engine  Builders  in  the 
United  States.  Illustrated  by  30  large  and  elaborate  plates.  4to.  $5.00 

.  CDWARDS.— The  Practical  Steam  Engineer's  Guide 

In  the  Design,  Construction,  and  Management  of  American  Stationary, 
Portable,  and  Steam  Fire- Engines,  Steam  Pumps,  Boilers,  Injectors, 
Governors,  Indicators,  Pistons  and  Rings,  Safety  Valves  and  Steam 
Gauges.  For  the  use  of  Engineers,  Firemen,  and  Steam  Users.  B> 
EMORY  EDWARDS.  Illustrated  by  119  engravings.  A2O  pages. 
121110.  ..........  $2  50 

EISSLER.— The  Metallurgy  of  Gold  : 

A  Practical  Treatise  on  the  Metallurgical  Treatment  of  Gold-Bear- 
ing  Ores,  including  trie  Processes  of  Concentration  and  Chlorination, 
and  the  Assaying,  Melting,  and  Refining  of  Gold.  By  M.  EISSLER. 
With  132  Illustrations.  I2mo. $5.00 

EISSLER.— The  Metallurgy  of  Silver  : 

A  Practical  Treatise  on  the  Amalgamation,  Roasting,  and  Lixiviation 
of  Silver  Ores,  including  the  Assaying,  Melting,  and  Refining  of 
Silver  Bullion.  By  M.  EISSLER.  124  Illustrations.  336  pp. 
I2mo $4.25 

ELDER. — Conversations  on  the  Principal  Subjects  of  Political 

Economy. 
By  DR.  WILLIAM  ELDER.    8vo #2.50 

ELDER.— Questions  of  the  Day, 

Economic  and  Social.     By  DR.  WILLIAM  ELDER.     8vo.     .      $3.00 

ERNI. — Mineralogy  Simplified. 

Easy  Methods  of  Determining  and  Classifying  Minerals,  including 
Ores,  by  means  of  the  Blowpipe,  and  by  Humid  Chemical  Analysis, 
based  on  Professor  von  Kobell's  Tables  for  the  Determination  of 
Minerals,  with  an  Introduction  to  Modern  Chemistry.  By  HENRY 
ERNI,  A.M.,  M.D.,  Professor  of  Chemistry.  Second  Edition,  rewritten, 
enlarged  and  improved.  I2mo.  ....  $3  °° 

FAIRBAIRN.— The  Principles  of  Mechanism  and  Machinery 

of  Transmission  • 

Comprising  the  Principles  of  Mechanism,  Wheels,  and  Pulleys, 
Strength  and  Proportions  of  Shafts,  Coupling  of  Shafts,  and  Engag- 
ing  and  Disengaging  Gear.  By  SIR  WILLIAM  FAIRBAIRN,  Bart 
C.  E.  Beautifully  Illustrated  by  over  150  wood-cuts.  In  one 
volume.  I2mo $2.50 

FLEMING.— Narrow  Gauge  Railways  in  America. 
A  Sketch  of  their  Rise,  Progress,  and  Success.     Valuable  Statistics 
as  to  Grades,  Curves,  Weight  of  Rail,  Locomotives,  Cars,  etc.     By 
HOWARD  FLEMING.     Illustrated,  8vo £i  oo 

FORSYTH.— Book  of  Designs  for  Headstones,   Mural,   and 

oth&r  Monuments : 

Containing  78  Designs.  By  JAMES  FORSYTH.  With  an  Introduction 
by  CHARLES  BOUTELL,  M.  A.  4  to.,  cloth  .  .  -  $5  °° 


HENRY   CAREY   BAIRD   &   CO.'S   CATALOGUE.        '3 


^RANKEL— HUTTER.— A  Practical  Treatise  on  the  Manu- 
facture of  Starch,  Glucose,  Starch-Sugar,  and  Dextrine: 
Based  on  the  German  of  LADISLAUS  VON  WAGNER,  Professor  in  the 
Royal  Technical  High  School,  Buda-Pest,  Hungary,  and  other 
authorities.  By  JULIUS  FRANKEL,  Graduate  of  the  Polytechnic 
School  of  Hanover.  Edited  by  ROBERT  HUTTER,  Chemist,  Practical 
Manufacturer  of  Starch-Sugar.  Illustrated  by  58  engravings,  cover- 
ing every  branch  of  the  subject,  including  examples  of  the  most 
Recent  and  Best  American  Machinery.  Svo.,  344  pp.  .  $3.50 

GARDNER. — The  Painters  Encyclopaedia: 
Containing  Definitions  of  all  Important  Words  in  the  Art  of  Plain 
and  Artistic  Painting,  with  Details  of  Practice  in  Coach,  Carriage, 
Railway  Car,  House,  Sign,  and  Ornamental  Painting,  including 
Graining,  Marbling,  Staining,  Varnishing,  Polishing,  Lettering, 
Stenciling,  Gilding,  Bronzing,  etc.  By  FRANKLIN  B.  GARDNER. 
158  Illustrations.  I2ino.  427  pp $2.OC 

GARDNER. — Everybody's  Paint  Book: 

A  Complete  Guide  to  the  Art  of  Outdoor  and  Indoor  Painting,  De- 
signed for  the  Special  Use  of  those  who  wish  to  do  their  own  work, 
and  consisting  of  Practical  Lessons  in  Plain  Painting,  Varnishing, 
Polishing,  Staining,  P?prr  Hanging,  Kalsomining,  etc.,  as  well  as 
Directions  for  Renovating  Furniture,  and  Hints  on  Artistic  Work  for 
Home  Decoration.  38  Illustrations.  I2mo.,  183  pp.  .  $1.00 

'SEE. — The  Goldsmith's  Handbook : 

Containing  full  instructions  for  the  Alloying  and  Working  of  Gold, 
including  the  Art  of  Alloying,  Melting,  Reducing,  Coloring,  Cql 
lecting,  and  Refining;  the  Processes  of  Manipulation,  Recovery  of 
Waste;  Chemical  and  Physical  Properties  of  Gold;  with  a  New 
System  of  Mixing  its  Alloys ;  Solders,  Enamels,  and  other  Useful 
Rules  and  Recipes.  By  GEORGE  E.  GEE.  I2mo.  „  .  $1-7$ 

GEE. — The  Silversmith's  Handbook  : 

Containing  full  instructions  fur  the  Alloying  and  Working  of  Silver, 
including  the  different  modes  of  Refining  ?.nd  Melting  the  Metal ;  its 
Solders ;  the  Preparation  of  Imitation  Alloys  ;  Methods  of  Manipula- 
tion ;  Prevention  of  Waste  ;  Instructions  for  Improving  and  Finishing 
the  Surface  of  the  Work  ;  together  with  other  Useful  Information  and 
Memoranda.  By  GEORGE  E.  GEE.  Illustrated.  I2mo.  $1-75 

GOTHIC  ALBUM  FOR  CABINET-MAKERS: 

Designs  for  Gothic  Furniture.     Twenty-three  plates.     Oblong  $2.00 

3RANT. — A  Handbook  on  the  Teeth  of  Gears  : 
Their  Curves,  Properties,  and  Practical  Construction.     By  GEORGK 
B.  GRANT.     Illustrated.     Third  Edition,  enlarged.     Svo.          $1  oo 

GREEN  WOOD.— Steel  and  Iron: 

Comprising  the  Practice  and  Theory  of  the  Several  Methods  Pur 
sued  in  their  Manufacture,  and  of  their  Treatment  in  the  Rolling- 
Mills,  the  Forge,  and  the  Foundry.  By  WILLIAM  HENRY  GREEN- 
WOOD, F.  C.  S.  With  97  Diagrams,  536  pages.  I2ino.  $2.00 


HENRY   CAREY   BAIRD   &   CO.'S  CATALOGUE. 


GREGORY. — Mathematics  for  Practical  Men : 

Adapted  to  the  Pursuits  of  Surveyors,  Architects,  Mechanics,  and 
Civil  Engineers.  By  OLINTHUS  GREGORY.  8vo.,  plates  $3.00. 

GRISWOLD. — Railroad  Engineer's  Pocket  Companion  for  thi 

Field : 

Comprising  Rules  for  Calculating  Deflection  Distances  and  Angles. 
Tangential  Distances  and  Angles,  and  all  Necessary  Tables  for  En 
gineers;  also  the  Art  of  Levelling  from  Preliminary  Survey  to  the 
Construction  of  Railroads,  intended  Expressly  for  the  Young  En- 
gineer, together  with  Numerous  Valuable  Rules  and  Examples.  By 
W.  GRISWOLU.  lamo.,  tucks $i-75 

GRUNER. — Studies  of  Blast  Furnace  Phenomena: 

By  M.  L.  GRUNER,  President  of  the  General  Council  of  Mines  o5 
France,  and  lately  Professor  of  Metallurgy  at  the  Ecole  des  Mines. 
Translated,  with  the  author's  sanction,  with  an  appendix,  by  L.  D. 
B.  GORDON,  F.  R.  S.  E.,  F.  G.  S.  8vo.  .  .  .  $2.$< 

Hand-Book  of  Useful  Tables  for  the  Lumberman,  Farmet  and 

Mechanic: 

Containing  Accurate  Tables  of  Logs  Reduced  to  Inch  Board  Meas- 
ure,  Plank,  Scantling  and  Timber  Measure;  Wages  and  Rent,  by 
Week  or  Month;  Capacity  of  Granaries,  Bins-  and  Cisterns;  Land 
Measure,  Interest  Tables,  with  Directions  for  Finding  the  Interest  on 
any  sum  at  4,  5,  6,  7  and  8  per  cent.,  and  many  other  Useful  Tables. 
32  mo.,  boards.  186  pages .25 

HASERICK.— The  Secrets  of  the  Art  of  Dyeing  Wool,  Cotton, 

and  Linen, 

Including  B'eaching  and  Coloring  Wool  and  Cot'»m  Hosiery  and 
Random  Yarns.  A  Treatise  based  on  Economy  an<i  Practice.  By 
E.  C.  HASERICK.  Illustrated  by  323  Dyed  Patterns  of  the  Yarni 
or  Fabrics.  8vo $7-5O 

HATS  AND  FELTING: 

A  Practical  Treatise  on  their  Manufacture.  By  a  Pmctical  Hatter. 
Illustrated  by  Drawings  of  Machinery,  etc.  8vo.  .  .  $I.2J 

HOFFER. — A   Practical   Treatise   on   Caoutchouc  and   Gutta 

Percha, 

Comprising  the  Properties  of  the  Raw  Materials,  and  the  manner  nr 
Mixing  and  Working  them  ;  with  the  Fabrication  of  Vulcanized  and 
Hard  Rubbers,  Caoutchouc  ind  Gutta  Percha  Compositions,  Water- 
proof Substances,  Elastic  Tissues,  the  Utilization  of  Waste,  etc.,  eu. 
From  the  German  of  RAIMUND  HOFFER.  By  W.  T.  ERANNT. 
Illustrated  I2mo.  .  ......  $2.50 

HAUPT. — Street  Railway  Motors: 

With  Descriptions  and  Cost  of  Plants  and  Operation  of  the  Variou* 
Systems  now  in  Use.  I2mo.  .....  $1-75 


HENRY   CAREY   BAIRD   &   CO.'S   CATALOGUE.        15 

HAUPT— RHAWN.— A  Move  for  Better  Roads: 

Essays  on  Road-making  and  Maintenance  and  Road  Laws,  for 
which  Prizes  or  Honorable  Mention  were  Awarded  through  the 
University  of  Pennsylvania  by  a  Committee  of  Citizens  of  Philadel- 
phia, with  a  Synopsis  of  other  Contributions  and  a  Review  by  the 
Secretary,  LEWIS  M.  HAUPT,  A.  M.,  C.  E. ;  also  an  Introduction  by 
WILLIAM  II.  RHAWN,  Chairman  of  the  Committee.  319  pages. 
8vo. $2.00 

HUGHES. — American  Miller  and  Millwright's  Assistant: 
By  WILLIAM  CARTER  HUGHES.    121110.     ....        $1.50 

HULME.— Worked  Examination  Questions  in  Plane  Geomet- 
rical Drawing  : 

For  the  Use  of  Candidates  for  the  Royal  Military  Academy,  Wool- 
wich; the  Royal  Military  College,  Sandhurst ;  the  Indian  Civil  En- 
gineering College,  Cooper's  Hill  ;  Indian  Public  Works  and  Tele- 
graph Departments ;  Royal  Marine  Light  Infantry;  the  Oxford  and 
Cambridge  Local  Examinations,  etc.  By  F.  EDWARD  HULME,  F.  L. 
S.,  F.  S.  A.,  Art-Master  Marlborough  College.  Illustrated  by  300 
examples.  Small  quartc *  $2.50 

JERVIS.— Railroad  Property: 

A  Treatise  on  the  Construction  and  Management  of  Railways; 
designed  to  afford  useful  knowledge,  in  the  popular  style,  to  the 
holders  of  this  class  of  property  ;  as  well  as  Railway  Managers,  Offi- 
cers, and  Agents.  By  JOHN  B.  JERVIS,  late  Civil  Engineer  of  the 
Hudson  River  Railroad,  Croton  Aqueduct,  etc.  i2mo.,  cloth  $2.oc 

KEENE.— A  Hand-Book  of  Practical  Gauging: 

For  the  Use  of  Beginners,  to  which  is  added  a  Chapter  on  Distilla- 
tion, describing  the  process  in  operation  at  the  Custom- House  for 
ascertaining  the  Strength  of  Wines.  By  JAMES  B.  KEENE,  of  H.  M. 
Customs.  8vo. .  .  $1.25 

KELLEY. — Speeches,  Addresses,  and  Letters  on  Industrial  and 

Financial  Questions : 
By  HON.  WILLIAM  I).  KELLEY,  M.  C.     544  pages,  8vo.  .         $2.5u 

KELLOGG.— A  New  Monetary  System  : 

The   only  means  of  Securing   the   respective   Rights  of  Labor  and 
Property,  and  of  Protecting  the  Public  from   Financial  Revulsions. 
By  EDWARD  KELLOGG.     Revised  from  his  work  on  "  Labor  and 
other    Capital."     With    numerous    additions    from    his    manuscript 
Edited  by  MARY  KELLOGG  PUTNAM.     Fifth  edition.    To  which  i' 
added  a  Biographical  Sketch  of  the  Author.     One  volume,  izmo. 
Paper  cover        .          .          .          ......         f 1 .00 

Bound  in  cloth 1.25 

KEM  LO.— Watch-Repairer's  Hand-Book : 
Being  a  Complete  Guide  to  the  Young  Beginner,  in  Taking  Apart, 
Putting  Together,  and  Thoroughly  Cleaning  the  English  Lever  and 
other  Foreign  Watches,  and  all  American  Watches.     By  F.  KfiMLO, 
Practical  Watchmaker.     With  Illustrations.      I2mo.  .         $1.25 


16          HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 

KENTISH. — A  Treatise  on  a  Box  of  Instruments, 

And  the  Slide  Rule ;  with  the  Theory  of  Trigonometry  and  Log* 
rithms,  including  Practical  Geometry,  Surveying,  Measuring  of  Tim- 
her,  Cask  and  Malt  Gauging,  Heights,  and  Distances.  By  THOMA? 
KENTISH.  In  one  volume.  I2mo.  ....  $1.25 

KERL. — The  Assayer's  Manual: 

An  Abridged  Treatise  on  the  Docimastic  Examination  of  Ores,  and 
Furnace  and  other  Artificial  Products.  By  BRUNO  KERL,  Professor 
in  the  Royal  School  of  Mines.  Translated  from  the  German  by 
WILLIAM  T.  BRANNT.  Second  American  edition,  edited  with  Ex- 
tensive Additions  by  F.  LYNWOOD  GARRISON,  Member  of  the 
American  Institute  of  Mining  Engineers,  etc.  Illustrated  by  87  en- 
gravings. 8vo $3-OC 

KICK.— Flour  Manufacture. 

A  Treatise  on  Milling  Science  and  Practice.  By  FREDERICK  KICK 
Imperial  Regierungsrath,  Professor  of  Mechanical  Technology  in  the 
imperial  German  Polytechnic  Institute,  Prague.  Translated  from 
the  second  enlarged  and  revised  edition  with  supplement  by  H.  H. 
P.  POWLES,  Assoc.  Memb.  Institution  of  Civil  Engineers.  Illustrated 
with  28  Plates,  and  167  Wood-cuts.  367  pages.  8vo.  .  $10.00 

KINGZETT.— The   History,   Products,  and   Processes  of  the 

Alkali  Trade : 

Including  the  most  Recent  Improvements.  By  CHARLES  THOMAS 
KINGZETT,  Consulting  Chemist.  With  23  illustrations.  8vo.  $2.50 

KIRK. — The  Founding  of  Metals : 

A  Practical  Treatise  on  the  Melting  of  Iron,  with  a  Description  of  the 
Founding  of  Alloys;  also,  of  all  the  Metals  and  Mineral  Substances 
used  in  the  Art  of  Founding.  Collected  from  original  sources.  B> 
EDWARD  KIRK,  Practical  Foundryman  and  Chemist.  Illustrated. 
Third  edition.  8vo.  .......  $2.50 

LANDRIN.— A  Treatise  on  Steel : 

Comprising  its  Theory,  Metallurgy,  Properties,  Practical  Working, 
and  Use.  By  M.  H.  C.  LANDRIN,  JR.,  Civil  Engineer.  Translated 
from  the  French,  with  Notes,  by  A.  A.  FESQUET,  Chemist  and  En 
gineer.  With  an  Appendix  on  the  Bessemer  and  the  Martin  Pro- 
nesses  for  Manufacturing  Steel,  from  the  Report  of  Abram  S.  Hewitt 
United  States  Commissioner  to  the  Universal  Exposition,  Paris,  1867. 

I2IRO $3-°° 

LANGBEIN. — A  Complete  Treatise  on  the  Electro-Deposition 

of  Metals : 

Translated  from  the  German,  with  Additions,  by  WM.  T.  BRANNT. 
125  illustrations.  8vo $4.00 

LARDNER.— The  Steam-Engine : 

For  the  Use  of  Beginners.     Illustrated.     I2mo.  75 

i^EHNER.— The  Manufacture  of  Ink: 

Comprising  the  Raw  Materials,  and  the  Preparation  df  Waiting, 
Copying  and  Hektograph  Inks,  Safety  Inks,  Ink  Extracts  and  Pow- 
ders, etc.  Translated  from  the  German  of  SIGMUND  LEHNER,  with 
additions  by  WILLIAM  T.  BRANNT.  Illustrated.  12010.  $2.00 


HENRY   CARE\    BAIRD   &   CO.'S   CATALOGUE.        17 

LARKIN. — The  Practical  Brass  and  Iron  Founder's  Guide: 
A  Concise  Treatise  on  Brass  Founding,  Moulding,  the  Metals  and 
their  Alloys,  etc. ;  to  which  are  added  Recent  Improvements  in  thfl 
Manufacture  of  Iron,  Steel  by  the  Bessemer  Process,  etc.,  etc.  By 
JAMES  LARKIN,  late  Conductor  of  the  Brass  Foundry  Department  in 
Keany,  Neafie  &  Co.'s  Penn  Works,  Philadelphia.  New  edition, 
revised,  with  extensive  additions.  12:110.  .  .  .  $2.50 

LEROUX. — A    Practical     Treatise    on    the    Manufacture    ol 

Worsteds  and  Carded  Yarns  : 

Comprising  Practical  Mechanics,  with  Rules  and  Calculations  applied 
to  Spinning ;  Sorting,  Cleaning,  and  Scouring  Wools ;  the  English 
and  French  Methods  of  Combing,  Drawing,  and  Spinning  Worsteds, 
and  Manufacturing  Carded  Yarns.  Translated  from  the  French  of 
CHARLES  LEROUX,  Mechanical  Engineer  and  Superintendent  of  a 
Spinning-Mill,  by  HORATIO  PAINE,  M.  D.,  and  A.  A.  FESQUET, 
Chemist  and  Engineer.  Illustrated  by  twelve  large  Plates.  To  which 
is  added  an  Appendix,  containing  Extracts  from  the  Reports  of  the 
International  Jury,  and  of  the  Artisans  selected  by  the  Commutes 
appointed  by  the  Council  of  the  Society  of  Arts,  London,  on  Woolen 
and  Worsted  Machinery  and  Fabrics,  as  exhibited  in  the  Paris  UnU 
versa!  Exposition,  1867.  8vo.  $5.00 

LEFFEL. — The  Construction  of  Mill-Dams  : 
Comprising  also  the  Building  of  Race  and  Reservoir  Embankments 
and  Head-Gates,  the   Measurement  of  Streams,  Gauging  of  Water 
Supply,  etc.     By  JAMES  LEFFEL  &  Co.    Illustrated  by  58  engravings. 
8vo. $2.50 

LESLIE.— Complete  Cookery: 

Directions  for  Cookery  in  its  Various  Branches.  By  Miss  LESLIE. 
Sixtieth  thousand.  Thoroughly  revised,  with  the  addition  of  New 
Receipts.  I2mo. $1.50 

LE  VAN. — The  Steam  Engine  and  the  Indicator  : 

Their  Origin  and  Progressive  Development ;  including  the  Most 
Recent  Examples  of  Steam  and  Gas  Motors,  together  with  the  Indi- 
cator, its  Principles,  its  Utility,  and  its  Application.  By  WILLIAM 
BARNET  LE  VAN.  Illustrated  by  205  Engravings,  chiefly  of  Indi- 
cator-Cards.  469  pp.  8vo.  ......  $4.00 

LIEBER. — Assayer's  Guide  : 

Or,  Practical  Directions  to  Assayers,  Miners,  and  Smelters,  for  the 
Tests  and  Assays,  by  Heat  and  by  Wet  Processes,  for  the  Ores  of  all 
the  principal  Metals,  of  Gold  and  Silver  Coins  and  Alloys,  and  of 
Coal,  etc.  By  OSCAR  M.  LIEBER.  Revised.  283  pp.  I2mo.  $1.50 

Ixickwood's  Dictionary  of  Terms  : 

Used  in  the  Practice  of  Mechanical  Engineering,  embracing  those 
Current  in  the  Drawing  Office,  Pattern  Shop,  Foundry,  Fitting,  Turn- 
Ing,  Smith's  and  Boiler  Shops,  etc.,  etc.,  comprising  upwards  of  Six' 
Thousand  Definitions.  Edited  by  a  Foreman  Pattern  Maker,  author 
of  "  Pattern  Making."  417  pp.  I2mo.  .  .  .  $3.00 


1 8         HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 

LUKIN.— Amongst  Machines : 

Embracing  Descriptions  of  the  various  Mechanical  Appliances  used 
in  the  Manufacture  of  Wood,  Metal,  and  other  Substances.  I2mo. 

4l.7C 

LUKIN.— The  Boy  Engineers : 
What  They  Did,  and  How  They  Did  It.     With  30  plates.    l8mo. 

>i-75 

LUKIN. — The  Young  Mechanic  i 

Practical  Carpentiy.  Containing  Directions  for  the  Use  of  all  kinds 
of  Tools,  and  for  Construction  of  Steam- Engines  and  Mechanical 
Models,  including  the  Art  of  Turning  in  Wood  and  Metal.  By  JOHN 
LUKIN,  Author  of  "The  Lathe  and  Its  Uses,"  etc.  Illustrated, 
lamo $i-75 

MAIN  and  BROWN.— Questions  on  Subjects  Connected  with 

the  Marine  Steam-Engine : 

And  Examination  Papers;  with  Hints  for  their  Solution.  By 
THOMAS  J.  MAIN,  Professor  of  Mathematics,  Royal  ^laval  College, 
and  THOMAS  BROWN,  Chief  Engineer,  R.  N.  I2mo.,  cloth  .  jii.oo 

MAIN  and  BROWN. — The  Indicator  and  Dynamometer: 
With  their  Practical  Applications  to  the  Steam-Engine.     By  THOMAS 
J.  MAIN,   M.  A.  F.  R.,  Ass't   S.   Professor   Royal   Naval   College, 
Portsmouth,  and  THOMAS  BROWN,  Assoc.  Inst.  C.  E.,  Chief  Engineer 
R.  N.,  attached  to  the  R.  N.  College.     Illustrated.     8vo.  .         $1.00 

MAIN  and  BROWN. — The  Marine  Steam-Engine. 
By  THOMAS  J.  MAIN,  F.  R.  Ass't  S.  Mathematical  Professor  at  the 
Royal    Naval    College,   Portsmouth,  and   THOMAS   BROWN,  Assoc. 
Inst.  C.  E.,  Chief  Engineer  R.  N.     Attached  to  the  Royal  Naval 
College.     With  numerous  illustrations.     8vo. 

MAKINS. — A  Manual  of  Metallurgy: 

By  GEORGE  HOGARTH  MAKINS.  100  engravings.  Second  edition 
rewritten  and  much  enlarged.  I2mo.,  592  pages  .  .  $3.00 

MARTIN.— Screw-Cutting  Tables,  for  the  Use  of  Mechanica> 

Engineers  : 

Showing  the  Proper  Arrangement  of  Wheels  for  Cutting  the  Threads 
of  Screws  of  any  Required  Pitch ;  with  a  Table  for  Making  the  Uni- 
versal Gas-Pipe  Thread  and  Taps.  By  W.  A.  MARTIN,  Engineer 
8vo. 5r. 

MICHELL. — Mine  Drainage: 

Being  a  Complete  and  Practical  Treatise  on  Direct-Acting  Under 
ground  Steam  Pumping  Machinery.  With  a  Description  of  a  large 
number  of  the  best  known  Engines,  their  General  Utility  and  the 
Special  Sphere  of  their  Action,  the  Mode  of  their  Application,  »nd 
their  Merits  compared  with  other  Pumping  Machinery.  By  STEPHEN 
MICHELL.  Illustrated  by  137  engravings.  8vo.,  277  pages  .  $6.00 

MOLESWORTH.— Pocket-Book    of    Useful     Formulae     and 

Memoranda  for  Civil  and  Mechanical  Engineers. 
By  GUILFORD  L.  MOLESWORTH,  Member  of  the  Institution  of  Civil 
Engineers,  Chief  Resident   Engineer  of  the  Ceylon  Railway.     Full- 
buund  in  Pocket-book  form      .-.--• 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.          19 

MOORE. — The  Universal  Assistant  and  the  Complete  Me- 
chanic : 

Containing  over  one  million  Industrial  Facts,  Calculations,  Receipts, 
Processes,  Trades  Secrets,  Rules,  Business  Forms,  Legal  Items,  Etc., 
in  every  occupation,  from  the  Household  to  the  Manufactory.  By 
R.  MOORE.  Illustrated  by  500  Engravings.  I2mo.  .  $2.50 

MORRIS. — Easy  Rules  for  the  Measurement  of  Earthworks  : 
By  means  of  the  Prismoidal  Formula.  Illustrated  with  Numerous 
Wood-Cuts,  Problems,  and  Examples,  and  concluded  by  an  Exten- 
sive Table  for  finding  the  Solidity  in  cubic  yards  from  Mean  Areas. 
The  whole  being  adapted  for  convenient  use  by  Engineers,  Surveyors, 
Contractors,  and  others  needing  Correct  Measurements  of  Earthwork. 
By  ELWOOD  MORRIS,  C.  E.  8vo #1.50 

MAUCHLINE.— The  Mine  Foreman's  Hand-Book 

Of  Practical  and  Theoretical  Information  on  the  Opening,  Venti- 
lating, and  Working  of  Collieries.  Questions  and  Answers  on  Prac- 
tical and  Theoretical  Coal  Mining.  Designed  to  Assist  Students  and 
Others  in  Passing  Examinations  for  Mine  Foremanships.  By 
ROBERT  MAUCHLINE,  Ex-Inspector  of  Mines.  A  New,  Revised  and 
Enlarged  Edition.  Illustrated  by  114  engrarings.  8vo.  337 
pages #3-75 

NAPIER. — A  System  of  Chemistry  Applied  to  Dyeing. 
By  JAMES  NAPIER,  F.  C.  S.  A  New  and  Thoroughly  Revised  Edi- 
tion. Completely  brought  up  to  the  present  state  of  the  Sciencet 
including  the  Chemistry  of  Coal  Tar 'Colors,  by  A.  A.  FESQUET,. 
Chemist  and  Engineer.  With  an  Appendix  on  Dyeing  and  Calico; 
Printing,  as  shown  at  the  Universal  Exposition,  Paris,  1867.  Illus- 
trated. 8vo.  422  pages $3-5°^ 

NEVILLE.— Hydraulic  Tables,  Coefficients,  and  Formula,  foi 
finding  the  Discharge  of  Water  from  Orifices,  Notches^ 
Weirs,  Pipes,  and  Rivers  : 

Third  Edition,  with  Additions,  consisting  of  New  Formulae  for  the 
Discharge  from  Tidal  and  Flood  Sluices  and  Siphons ;  general  infor- 
mation on  Rainfall,  Catchment-Basins,  Drainage,  Sewerage,  Wa;e« 
Supply  for  Towns  and  Mill  Power.  By  JOHN  NEVILLE,  C.  E.  M.  R 
I.  A. ;  Fellow  of  the  Royal  Geological  Society  of  Ireland.  Thick, 
I2mo. #5.50 

NEWBERY.— Gleanings     from     Ornamental     Art    of     every 

style : 

Drawn  from  Examples  in  the  British,  South  Kensington,  Indian, 
Crystal  Palace,  and  other  Museums,  the  Exhibitions  of  1851  and 
1862,  and  the  best  English  and  Foreign  works.  In  a  series  of  100 
exquisitely  drawn  Plates,  containing  many  hundred  examples.  B* 
ROBERT  NEWBERY.  410. $12.50 

NICHOLLS.  —The  Theoretical  and  Practical  Boiler- Maker  ant? 

Engineer's  Reference  Book: 

Containing  a  variety  of  Useful  Information  for  Employers  of  Labot 
Foremen  and  Working  Boiler-Makers.  Iron,  Copper,  and  Tinsmiths 


20        HENRY  CAREY  BA1RD  &  CO.'S  CATALOGUE. 

Draughtsmen,  Engineers,  the  General  Steam-using  Public,  and  for  tha 
Use  of  Science  Schools  and  Classes.  By  SAMUEL  NICHOLLS.  Illus- 
trated  by  sixteen  plaies,  1 2mo. $2.50 

NICHOLSON.— A  Manual  of  the  Art  of  Bookbinding : 

Containing  full  instructions  in  the  different  Branches  of  Forwarding, 
Gilding,  and  Finishing.  Also,  the  Art  of  Marbling  Book-edges  and 
Paper.  By  JAMES  B.  NICHOLSON.  Illustrated.  I2mo.,  cloth  $2.25 

NICOLLS.— The  Railway  Builder: 

A  Hand-Book  for  Estimating  the  Probable  Cost  of  American  Rail* 
way  Construction  and  Equipment.  By  WILLIAM  J.  NICOLLS,  Civil 
Engineer.  Illustrated,  full  bound,  pocket-book  form  .  $2.00 

NORMANDY. — The  Commercial  Handbook  of  Chemical  An- 
alysis : 

Or  Practical  Instructions  for  the  Determination  of  the  Intrinsic  01 
Commercial  Value  of  Substances  used  in  Manufactures,  in  Trades, 
and  in  the  Arts.  By  A.  NORMANDY.  New  Edition,  Enlarged,  and 
to  a  great  extent  rewritten.  By  HENRY  M.  NOAD,  Ph.D.,  F.R.S., 
thick  I2mo #5.00 

NORRIS. — A  Handbook  for  Locomotive  Engineers  and  Ma- 

chinists : 

Comprising  the  Proportions  and  Calculations  for  Constructing  Loco- 
motives;  Manner  of  Setting  Valves;  Tables  of  Squares,  Cubes,  Areas, 
etc.,  etc.  By  SEPTIMUS  NORRIS,  M.  E.  New  edition.  Illustrated, 
izrno |i.50 

NYSTROM. — A  New  Treatise  on  Elements  of  Mechanics : 
Establishing  Strict  Precision  in  the  Meaning  of  Dynamical  Terms : 
accompanied  with  an  Appendix  on  Duodenal  Arithmetic  and   Me- 
trology.    By  JOHN  W.  NYSTROM,  C.  E.     Illustrated.     8vo.       $2.00 

NYSTROM. — On  Technological  Education  and  the  Construc- 
tion of  Ships  and  Screw  Propellers : 

For  Naval  and  Marine  Engineers.  By  JOHN  W.  NYSTROM,  late 
Acting  Chief  Engineer,  U.  S.  N.  Second  edition,  revised,  with  addi- 
tional matter.  Illustrated  by  seven  engravings.  I2mo.  .  $1.50 

O'NEILL. — A  Dictionary  of  Dyeing  and  Calico  Printing: 

Containing  a  brief  account  of  all  the  Substances  and  Processes  in 
use  in  the  Art  of  Dyeing  and  Printing  Textile  Fabrics  ;  with  Practical 
Receipts  and  Scientific  Information.  By  CHARLES  O'NEILL,  Analy- 
tical Chemist.  To  which  is  added  an  Essay  on  Coal  Tar  Colors  and 
their  application  to  Dyeing  and  Calico  Printing.  By  A.  A.  FESQUET, 
Chemist  and  Engineer.  With  an  appendix  on  Dyeing  and  Calico 
Printing,  as  shown  at  the  Universal  Exposition,  Paris,  1867-  8vo., 
491  pages  .  -  .  13.50 

ORTON. — Underground  Treasures1. 

How  and  Where  to  Find  Them.  A  Key  for  the  Ready  Determination 
of  all  the  Useful  Minerals  within  the  United  States.  By  JAMES 
ORTON,  A.M.,  Late  Professor  of  Natural  History  in  Vassar  College, 
N.  Y.;  Cor.  Mem.  of  the  Academy  of  Natural  Sciences,  Philadelphia, 
and  of  the  Lyceum  of  Natural  History,  New  York ;  author  of  the 
"Andes  and  the  Amazon,"  etc.  A  New  Edition,  with  Additions. 
Illustrated  I.» 


HENRY  CAREY  BAlRD   &   CO.'S   CATALOGUE.       25 


OSBORN.— The  Prospector's  Field  Book  and  Guide: 

In  the  Search  for  and  the  Easy  Determination  of  Ores  and  Other 
Useful  Minerals.  By  Prof.  H.  S.  OSBORN,  LL.  D.,  Author  of 
"  The  Metallurgy  of  Iron  and  Steel ; "  "A  Practical  Manual  of 
Minerals,  Mines,  and  Mining."  Illustrated  by  44  Engravings. 
I2mo $I-5O 

OSBORN. — A  Practical  Manual  of  Minerals,  Mines  and  Min- 
ing : 

Comprising  the  Physical  Properties,  Geologic  Positions,  Local  Occur- 
rence and  Associations  of  the  Useful  Minerals ;  their  Methods  of 
Chemical  Analysis  and  Assay :  together  with  Various  Systems  of 
Excavating  and  Timbering,  Brick  and  Masonry  Work,  during  Driv- 
ing, Lining,  Bracing  and  other  Operations,  etc.  By  Prof.  H.  S. 
OSBORN,  LL.  D.,  Author  of  the  "  Metallurgy  of  Iron  and  Steel." 
Illustrated  by  171  engravings  from  original  drawings.  8vo.  $4.50 

OVERMAN. — Th«  Manufacture  of  Steel : 

Containing  the  Practice  and  Principles  of  Working  and  Making  Steel. 
A  Handbook  for  Blacksmiths  and  WTorkers  in  Steel  and  Iron,  Wagon 
Makers,  Die  Sinkers,  Cutlers,  and  Manufacturers  of  Files  and  Hard- 
ware, of  Steel  and  Iron,  and  for  Men  of  Science  and  Art.  By 
FREDERICK  OVERMAN,  Mining  Engineer,  Author  of  the  "  Manu- 
facture of  Iron,"  etc.  A  new,  enlarged,  and  revised  Edition.  By 
A.  A.  FESQUET,  Chemist  and  Engineer.  I2mo.  .  .  $1.50 

OVERMAN.— The  Moulder's  and  Founder's  Pocket  Guide  : 
A  Treatise  on  Moulding  and  Founding  in  Green-sand,  Dry-sand,  Loam, 
and  Cement;  the  Moulding  of  Machine  Frames,  Mill-gear,  Hollow- 
ware,  Ornaments,  Trinkets,  Bells,  and  Stftues;  Description  of  Moulds 
for  Iron,  Bronze,  Brass,  and  other  Metals ;  Plaster  of  Paris,  Sulphur, 
Wax,  etc. ;  the  Construction  of  Melting  Furnaces,  the  Melting  and 
Founding  of  Metals ;  the  Composition  of  Alloys  and  their  Nature, 
etc.,  etc.  By  FREDERICK  OVERMAN,  M.  E.  A  new  Edition,  to 
which  is  added  a  Supplement  on  Statuary  and  Ornamental  Moulding, 
Ordnance,  Malleable  Iron  Castings,  etc.  By  A.  A.  FESQUET,  Chem- 
ist and  Engineer.  Illustrated  by  44  engravings.  I2mo.  .  $2.OO 

PAINTER,  GILDER,  AND  VARNISHER'S  COMPANION, 
Containing  Rules  and  Regulations  in  everything  relating  to  the  Ant 
of  Painting,  Gilding,  Varnishing,  Glass-Staining,  Graining,  Marbling, 
Sign- Writing,  Gilding  on  Glass,  and  Coach  Painting  and  Varnishing; 
Tests  for  the  Detection  of  Adulterations  in  Oils,  Colors,  etc. ;  and  a 
Statement  of  the  Diseases  to  which  Painters  are  peculiarly  liable,  with 
the  Simplest  and  Best  Remedies.  Sixteenth  Edition.  Revised,  with 
an  Appendix.  Containing  Colors  and  Coloring — Theoretical  and 
Practical.  Comprising  descriptions  of  a  great  variety  of  Additional 
Pigments,  their  Qualities  and  Uses,  to  which  are  added,  Dryers,  and 
Modes  and  Operations  of  Painting,  etc.  Together  with  Chevreul'y 
Principles  of  Harmony  and  Contrast  of  Colors.  I2mo.  Cloth  $1.50 

^ALLETT. — The  Miller's,  Millwright's,  and  Engineer's  Guide. 
By  HENRY  PALLETT.  Illustrated.  i2mo.  .  .  -  $2.0* 


22          HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 

PERCY. — The  Manufacture  of  Russian  Sheet-Iron. 

By  JOHN  PERCY,  M.  D.,  F.  R.  S.,  Lecturer  on  Metallurgy  at  the 
Royal  School  of  Mines,  and  to  The  Advance  Class  of  Artillery 
Officers  at  the  Royal  Artillery  Institution,  Woolwich ;  Author  of 
"  Metallurgy."  With  Illustrations.  8vo.,  paper  .  .  50  eta. 

PERKINS.— Gas  and  Ventilation  : 

Practical  Treatise  on  Gas  and  Ventilation.  With  Special  Relation 
to  Illuminating,  Heating,  and  Cooking  by  Gas.  Including  Scientific 
Helps  to  Engineer-students  and  others.  With  Illustrated  Diagrams. 
By  E.  E.  PERKINS.  I2mo.,  cloth $1.25 

PERKINS  AND  STOWE.— A  New  Guide  to  the  Sheet-iron 

and  Boiler  Plate  Roller : 

Containing  a  Series  of  Tables  showing  the  Weight  of  Slabs  and  Pilei 
to  Produce  Boiler  Plates,  and  of  the  Weight  of  Piles  and  the  Sizes  of 
Bars  to  produce  Sheet-iron ;  the  Thickness  of  the  Bar  Gauga 
in  decimals ;  the  Weight  per  foot,  and  the  Thickness  on  the  Bar  or 
Wire  Gauge  of  the  fractional  parts  of  an  inch ;  the  Weight  per 
sheet,  and  the  Thickness  on  the  Wire  Gauge  of  Sheet-iron  of  various 
dimensions  to  weigh  1 12  Ibs.  per  bundle;  and  the  conversion  of 
Short  Weight  into  Long  Weight,  and  Long  Weight  into  Short. 
Estimated  and  collected  by  G.  H.  PERKINS  and  J.  G.  STOWE.  $2.50 

POWELL— CHANCE— HARRIS.— The    Principles  of  Glass 

Making. 

By  HARRY  J.  POWELL,  B.  A.  Together  with  Treatises  on  Crown  and 
Sheet  Glass;  by  HENRY  CHANCE,  M.  A.  And  Plate  Glass,  by  H. 
G.  HARRIS,  Asso.  M.  Inst.  C.  E.  Illustrated  i8mo.  .  $1.50 

PROCTOR.— A  Pockef-Book  of  Useful  Tables  and  Formulae 

for  Marine  Engineers : 

By  FRANK  'PROCTOR.  Second  Edition,  Revised  and  Enlarged. 
Full -bound  pocket-book  form $1.50 

REGNAULT. — Elements  of  Chemistry: 

By  M.  V.  REGNAULT.  Translated  from  the  French  by  T.  FORREST 
BETTON,  M.  D.,  and  edited,  with  Notes,  by  JAMES  C.  BOOTH,  Melter 
and  Refiner  U.  S.  Mint,  and  WILLIAM  L.  FABER,  Metallurgist  and 
Mining  Engineer.  Illustrated  by  nearly  700  wood-engravings.  Com- 
prising nearly  1,500  pages.  In  two  volumes,  8vo.,  cloth  .  $7.50 

RICHARDS.— Aluminium  : 

Its  History,  Occurrence,  Properties,  Metallurgy  and  Applications, 
including  its  Alloys.  By  JOSEPH  W.  RICHARDS,  A.  C.,  Chemist  and 
Practical  Metallurgist,  Member  of  the  Deutsche  Chemische  Gesell- 
schaft.  Illust.  Third  edition,  enlarged  and  revised  (1895)  •  $6.OO 

RIFFAULT,  VERGNAUD,  and  TOUSSAIMT.— A  Practical 

Treatise  on  the  Manufacture  of  Colors  for  Painting : 
Comprising  the  Origin,  Definition,  and  Classification  of  Colors;  the 
Treatment  of  the  Raw  Materials ;  the  best  Formulas  and  the  Newest 
Processes  for  the  Preparation  of  every  description  of  Pigment,  and 
ihe  Necessary  Apparatus  and  Directions  for  its  Use ;  Dryers ;  the 
Testing.  Application,  and  Qualities  of  Paints,  etc.,  etc.  By  MM. 
RIFFAULT,  VERGNAUD,  and  TOUSSAINT.  Revised  and  Edited  by  M. 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.  2? 

F.  MALEPEYRE.  Translated  from  the  French,  by  A.  A.  FESQTJET, 
Chemist  and  Engineer.  Illustrated  by  Eighty  engravings.  In  one 
vol..  8vo.,  659  pages $5.00 

ROPER. — A  Catechism  of  High-Pressure,  or  Non- Condensing 

Steam-Engines  : 

including  the  Modelling,  Constructing,  and  Management  of  Steam- 
Engines  and  Steam  Boilers.  With  valuable  illustrations.  By  STE- 
PHEN ROPER,  Engineer.  Sixteenth  edition,  revised  and  enlarged. 
i8mo.,  tucks,  gilt  edge $2.00 

ROPER.— Engineer's  Handy-Book: 

Containing  a  full  Explanation  of  the  Steam-Engine  Indicator,  and  its 
Use  and  Advantages  to  Engineers  and  Steam  Users.  With  Formulas 
for  Estimating  the  Power  of  all  Classes  of  Steam- Engines ;  also, 
Facts,  Figures,  Questions,  and  Tables  for  Engineers  who  wish  to 
qualify  themselves  for  the  United  States  Navy,  the  Revenue  Service, 
the  Mercantile  Marine,  or  to  take  charge  of  the  Better  Class  of  Sta- 
tionary Steam-Engines.  Sixth  edition.  i6rao.,  690  pages,  tucks, 
gilt  edge $3.50 

ROPER. — Hand-Book  of  Land  and  Marine  Engines  : 
Including  the  Modelling,  Construction,   Running,  and  Management 
of  Lane"  and  Marine  Engines  and  Boilers.     With  ilJustrations.     By 
STEPHEN  ROPER,  Engineer.    Sixth  edition.     I2mo.,tvcks,  gilt  edge. 

#3-50 
ROPER.— Hand-Book  of  the  Locomotive  : 

Including  the  Construction  of  Engines  and  Boilers,  and  the  Construc- 
tion, Management,  and  Running  of  Locomotives.  By  STEPHEN 
ROPER.  Eleventh  edition.  i8mo.,  tucks,  gilt  edge  .  $2.50 

ROPER. — Hand-Book  of  Modern  Steam  Fire-Engines. 

With  illustrations.  By  STEPHEN  ROPER,  Engineer.  Fourth  edition, 
I2mo.,  tucks,  gilt  edge $3.50 

ROPER. — Questions  and  Answers  for  Engineers. 

This  little  book  contains  all  the  Questions  that  Engineers  will  be 
asked  when  undergoing  an  Examination  for  the  purpose  of  procuring 
Licenses,  and  they  are  so  plain  that  any  Engineer  or  Fireman  of  or 
dinary  intelligence  may  commit  them  to  memory  in  a  short  time.  By 
STEPHEN  ROPER,  Engineer.  Third  edition  .  .  .  $3.00 

ROPER. — Use  and  Abuse  of  the  Steam  Boiler. 
By  STEPHEN  ROPER,  Engineer.     Eighth  edition,  with  illustrations. 
l8mo.,  tucks,  gilt  edge $2.OO 

ROSE. — The  Complete  Practical  Machinist : 

Embracing  Lathe  Work,  Vise  Work,  Drills  and  Drilling,  Taps  and 
Dies,  Hardening  and  Tempering,  the  Making  and  Use  of  Tools, 
Tool  Grinding,  Marking  out  Work,  etc.  By  JOSHUA  ROSE.  Illus- 
trated by  356  engravings.  Thirteenth  edition,  thoroughly  revised 
and  in  great  part  rewritten.  In  one  vol.,  121110.,  439  pages  $2.50 

HOSE.— Mechanical  Drawing  Self-Taught: 

Comprising  Instructions  in  the  Selection  and  Preparation  of  Drawing 
Instruments,  Elementary  Instruction  in  Practical  Mechanical  Draw 


24         HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 

ing,  together  with  Examples  in  Simple  Geometry  and  Elementary 
Mechanism,  including  Screw  Threads,  Gear  Wheels,  Mechanical 
Motions,  Engines  and  Boilers.  By  JOSHUA  ROSE,  M.  E.  Illustrated 
by  330  engravings.  8 vo.,  313  pages  ....  $4.00 

ROSE.— The  Slide- Valve  Practically  Explained: 

Embracing  simple  and  complete  Practical  Demonstrations  of  th» 
operation  of  each  element  in  a  Slide-valve  Movement,  and  illustrat- 
ing the  effects  of  Variations  in  their  Proportions  by  examples  care- 
fully selected  from  the  most  recent  and  successful  practice.  By 
JOSHUA  ROSE,  M.  E.  Illustrated  by  35  engravings  .  $1.00 

ROSS. — The  Blowpipe  in  Chemistry,  Mineralogy  and  Geology: 
Containing  all  Known  Methods  of  Anhydrous  Analysis,  many  Work- 
ing Examples,  and  Instructions  for  Making  Apparatus.  By  LIEUT.- 
COLONEL  W.  A.  Ross,  R.  A.,  F.  G.  S.  With  120  Illustrations. 
I2tno $2.00 

SHAW. — Civil  Architecture : 

Being  a  Complete  Theoretical  and  Practical  System  of  Building,  con- 
taining the  Fundamental  Principles  of  the  Art.  By  EDWARD  SHAW, 
Architect.  To  which  is  added  a  Treatise  on  Gothic  Architecture,  etc. 
By  THOMAS  W.  SILLOWAY  and  GEORGE  M.  HARDING,  Architects. 
The  whole  illustrated  by  102  quarto  plates  finely  engraved  on  copper. 
Eleventh  edition.  410. $7'5O 

SHUNK. — A  Practical  Treatise  on  Railway  Curves  and  Loca- 
tion, for  Young  Engineers. 

By  W.  F.  SHUNK,  C.  E.  I2mo.  Full  bound  pocket-book  form  $2.00 
SLATER. — The  Manual  of  Colors  and  Dye  Wares. 

By  J.  W.  SLATER.     1 2mo $3-oo 

SLOAN. — American  Houses  : 

A  variety  of  Original  Designs  for  Rural  Buildings.  Illustrated  bjr 
26  colored  engravings,  with  descriptive  references.  By  SAMUEL 
SLOAN,  Architect.  8vo. $1.50 

SLOAN. — Homestead  Architecture: 

Containing  Forty  Designs  for  Villas,  Cottages,  and  Farm-houses,  with 
Essays  on  Styic,  Construction,  Landscape  Gardening,  Furniture,  etc.> 
etc.  Illustrated  by  upwards  of  200  engravings.  By  SAMUEL  SLOAN, 
Architect.  8vo.  ........  $3.50 

SLOANE. — Hovt?e  Experiments  in  Science. 

By  T.  O'CoNOR  SLCANE,  E.  M.,  A.  M.,  Fh.  O.  Illustrated  by  gi 
engravings.  i2mo.  .......  $1.50 

SMEATON.— Builder's  Pocket-Companion : 

Containing  the  Elements  of  Building,  Surveying,  and  Architecture; 
with  Practical  Rules  and  Instructions  corrected  with  the  subject. 
By  A.  C.  SMEATON,  Civil  Engineer,  etc.  I2mo.  .  .  $i.5<* 

SMITH. — A  Manual  of  Political  Economy. 
By  E.  PESHINE  SMITH.    A  New  Edition,  to  which  is  added  a  full 
Index.     I2mo. £i  25, 


HENRY  CAREY  BAlRD  &  CO.'S  CATALOGUE.          25 


SMITH.— Parks  and  Pleasure-Grounds  : 

Or  Practical  Notes  on  Country  Residences,  Villas,  Public  Parks,  and 
Gardens.  By  CHARLES  H.  J.  SMITH,  Landscape  Gardener  and 
Garden  Architect,  etc.,  etc.  I2mo.  ....  $2.00 

SMITH. — The  Dyer's  Instructor : 

Comprising  Practical  Instructions  in  the  Art  of  Dyeing  Silk,  Cotton^ 
Wool,  and  Worsted,  and  Woolen  Goods ;  containing  nearly  800 
Receipts.  To  which  is  added  a  Treatise  on  the  Art  of  Padding;  anci 
the  Printing  of  Silk  Warps,  Skeins,  and  Handkerchiefs,  and  the 
various  Mordants  and  Colors  for  the  different  styles  of  such  work. 
By  DAVID  SMITH,  Pattern  Dyer.  I2mo.  .  .  .  $2.00 

SMYTH.— A  Rudimentary  Treatise  on  Coal  and  Coal-Mining. 
By  WARRINGTON  W.  SMYTH,  M.  A.,  F.  R.  G.,  President  R.  G.  S. 
of  Cornwall.  Fifth  edition,  revised  and  corrected.  With  numer- 
ous illustrations.  I2mo.  ......  $i«7S 

SNIVELY.— Tables  for  Systematic  Qualitative  Chemical  AnaK 

ysis. 
By  JOHN  H.  SNIVELY,  Phr.  D.     8vo.        ....        $1.00 

SNIVELY.— The  Elements  of  Systematic  Qualitative  •v.hemical 

Analysis : 

A  Hand-book  for  Beginners.    By  JOHN  H.  SNIVELY,  Phr.  D.    l6mo. 

$2.00 

STOKES. — The  Cabinet-Maker  and  Upholsterer's  Companion : 
Comprising  the  Art  of  Drawing,  as  applicable  to  Cabinet  Work ; 
Veneering,  Inlaying,  and  Buhl-Work ;  the  Art  of  Dyeing  and  Stain 
ing  Wood,  Ivory,  Bone,  Tortoise-Shell,  etc.  Directions  for  Lacker- 
ing, Japanning,  and  Virnishing;  to  make  French  Polish,  Glues. 
Cements,  and  Compos". i<~ as;  with  numerous  Receipts,  useful  to  work 
men  generally.  Bv  STOKES.  Illustrated.  A  New  Edition,  with 
an  Appendix  upor  /ench  Polishing,  Staining,  Imitating,  Varnishing, 
etc.,  etc.  I2mo $1-2$ 

STRENGTH  AND  OTHER  PROPERTIES  OF  METALS; 
Reports  of  Experiments  on  the  Strength  and  other  Properties  of 
Metals  for  Cannon.  With  a  Description  of  the  Machines  for  Testing 
Metals,  and  of  the  Classification  of  Cannon  in  service.  By  Officers- 
of  the  Ordnance  Department,  U.  S.  Army.  By  authority  of  the  Secre- 
taryofWar.  Illustrated  by  25  large  steel  plates.  Quarto  .  $10.00 

BULLIVAN. — Protection  to  Native  Industry. 

By  Sir  EDWARD  SULLIVAN,  Baronet,  author  of  "  Ten  Chapters  on 
Social  Reforms."  8vo.  .......  jSi.oo 

8ULZ. — A  Treatise  on  Beverages: 

Or  the  Complete  Practical  Bottler.  Full  instructions  for  Laboratory 
Work,  with  Original  Practical  P.ecipes  for  all  kinds  of  Carbonate-i 
Drinks,  Mineral  Waters,  Flavorings.  Extracts,  Syrups,  etc.  By 
CHAS.  HERMAN  SULZ,  Technical  Cherr.ist  ana  Practical  Bottler 
Illustrated  by  428  Engravings.  8i#  i*p.  Xvo  .  .  Jio.oc 


?6         HENRY  CAREY  BAIRt>  &  CO.'S  CATALOGUE. 

13YME. — Outlines  of  an  Industrial  Science. 

By  DAVID  SYME.     I2ino.          .        .  ...        #2.00 

TABLES     SHOWING     THE     WEIGHT     OF     ROUND, 

SQUARE,  AND  FLAT  BAR  IRON,  STEEL,  ETC., 
By  Measurement.     Cloth •  63 

TAYLOR.— Statistics  of  Coal : 

Including  Mineral  Bituminous  Substances  employed  in  Arts  and 
Manufactures ;  with  their  Geographical,  Geological,  and  Commercial 
Distribution  and  Amount  of  Production  and  Consumption  on  the 
American  Continent.  With  Incidental  Statistics  of  the  Iron  Manu- 
facture. By  R.  C.  TAYLOR.  Second  edition,  revised  by  S.  S.  HALDK- 
MAN.  Illustrated  by  five  Maps  and  many  wood  engravings.  8vo., 
cloth #6.00 

TEMPLETON. — The  Practical  Examinator  on  Steam  and  the 

Steam  -  Engine : 

With  Instructive  References  relative  thereto,  arranged  for  the  Use  of 
Engineers,  Students,  and  others.  By  WILLIAM  TEMPLETON,  En- 
gineer. I2mo.  ........  $1.00 

THAU  SING.— The  Theory  and  Practice  of  the  Preparation  of 

Malt  and  the  Fabrication  of  Beer: 

With  especial  reference  to  the  Vienna  Process  of  Brewing.  Elab- 
orated from  personal  experience  by  JULIUS  E.  THAUSING,  Professor 
at  the  School  for  Brewers,  and  at  the  Agricultural  Institute,  Modling, 
near  Vienna.  Translated  from  the  German  by  WILLIAM  T.  BRANNT, 
Thoroughly  and  elaborately  edited,  with  much  American  matter,  and 
according  to  the  latest  and  most  Scientific  Practice,  by  A.  SCHWARZ 
and  DR.  A.  H.  BAUER.  Illustrated  by  140  Engravings.  8vo.,  815 
pages $10.00 

THOMAS. — The  Modern  Practice  of  Photography: 
By  R.  W.  THOMAS,  F.  C.  S.    8vo.  ....  25 

THOMPSON.— Political  Economy.     With  Especial  Reference 

to  the  Industrial  History  of  Nations  : 

By  ROBERT  E.  THOMPSON,  M.  A.,  Professor  of  Social  Science  in  the 
University  of  Pennsylvania.  I2mo.  ....  $1.50 

THOMSON.— Freight  Charges  Calculator: 

By  ANDREW  THOMSON,  Freight  Agent.     24010.         .        .         $1.25 

TURNER'S  (THE)  COMPANION: 

Containing  Instructions  in  Concentric,  Elliptic,  and  Eccentric  Turn, 
ing;  also  various  Plates  of  Chucks,  Tools,  and  Instruments;  and 
Directions  for  using  the  Eccentric  Cutter,  Drill,  Vertical  Cutter,  and 
Circular  Rest;  with  Patterns  and  Instructions  for  working  them 
I2mo #1.25 

TURNING :   Specimens  of  Fancy  Turning  Executed  on  the 

Hand  or  Foot- Lathe  : 

With  Geometric,  Oval,  and  Eccentric  Chucks,  and  Elliptical  Cutting 
Trame.  By  an  Amateur.  Illustrated  by  30  exquisite  Photographs. 
4to. #3.00 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.          27 

VAILE. — Galvanized- Iron  Cornice-Worker's  Manual: 

Containing  Instructions  in  Laying  out  the  Different  Mitres,  and 
Making  Patterns  for  all  kinds  of  Plain  and  Circular  Work.  Also, 
Tables  of  Weights,  Areas  and  Circumferences  of  Circles,  and  other 
Matter  calculated  to  Benefit  the  Trade.  By  CHARLES  A.  VAILE. 
Illustrated  by  twenty-one  plates.  410 $5.00 

VILLE. — On  Artificial  Manures  : 

Their  Chemical  Selection  and  Scientific  Application  to  Agriculture. 
A  series  of  Lectures  given  at  the  Experimental  Farm  at  Vincennes, 
during  1867  and  1874-75.  By  M.  GEORGES  VILLE.  Translated  and 
Edited  by  WILLIAM  CROOKES,  F.  R.  S.  Illustrated  by  thirty-one 
engravings.  8vo.,  450  pages $6.00 

VILLE. — The  School  of  Chemical  Manures  : 
Or,  Elementary  Principles  in  the  Use  of  Fertilizing  Agents.     From 
the  French  of  M.  GEO.  VILLE,  by  A.  A.  FESQUET,  Chemist  and  En- 
gineer.    With  Illustrations.     I2mo.  ....         #1.25 

VOGDES. — The  Architect's  and  Builder's  Pocket-Companion 

and  Price-Book : 

Consisting  of  a  Shoit  but  Comprehensive  Epitome  of  Decimals,  Duo- 
•decimals,  Geometry  and  Mensuration ;  with  Tables  of  United  States 
Measures,  Sizes,  Weights,  Strengths,  etc.,  of  Iron,  Wood,  Stone, 
Brick,  Cement  and  Concretes,  Quantities  of  Materials  in  given  Sizes 
•and  Dimensions  of  Wood,  Brick  and  Stone;  and  full  and  complete 
Bills  of  Prices  for  Carpenter's  Work  and  Painting ;  also,  Rules  for 
Computing  and  Valuing  Brick  and  Brick  Work,  Stone  Work,  Paint- 
Ing,  Plastering,  with  a  Vocabulary  of  Technical  Terms,  etc.  By 
FRANK  W.  VOGDES,  Architect,  Indianapolis,  Ind.  Enlarged,  revised, 
and  corrected.  In  one  volume,  368  pages,  full-bound,  pocket-book 

form,  gilt  edges $2.00 

Cloth         .  1.50 

VAN  CLEVE. — The  English  and  American  Mechanic: 

Comprising  a  Collection  of  Over  Three  Thousand  Receipts,  Rules, 
and  Tables,  designed  for  the  Use  of  every  Mechanic  and  Manufac- 
turer. By  B.  FRANK  VAN  CLEVE.  Illustrated.  500  pp.  i2mo.  $2.00 

WAHNSCHAFFE.— A  Guide  to  the  Scientific  Examination 

of  Soils : 

Comprising  Select  Methods  of  Mechanical  and  Chemical  Analysis 
and  Physical  Investigation.  Translated  from  the  German  of  Dr.  F4 
WAHNSCHAFFE.  With  additions  by  WILLIAM  T.  BRANNT.  Illus- 
trated by  25  engravings.  121110.  177  pages  .  .  .  $1.50 

WALL. — Practical  Graining : 

With  Descriptions  of  Colors  Employed  and  Tools  Used.  Illustrated 
by  47  Colored  Plates,  Representing  the  Various  Woods  Used  JK 
Interior  Finishing.  By  WILLIAM  E.  WALL.  8vo.  .  $2.50 

WALTON. — Coal-Mining  Described  and  Illustrated: 
By  THOMAS  H.  WALTON,  Mining  Engineer.     Illustrated  by  24  !arge 
and  elaborate  Plates,  after  Actual  Workings  and  Apparatus.    '#5.00 


28         HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 

WARE.— The  Sugar  Beet. 

Including  a  History  of  the  Beet  Sugar  Industry  in  Europe,  Varietie 
of  the  Sugar  Beet,  Examination,  Soils,  Tillage,  Seeds  and  Sowing 
Yield  and  Cost  of  Cultivation,  Harvesting,  Transportation,  Conserva- 
tion, Feeding  Qualities  of  the  Beet  and  of  the  Pulp,  etc.  By  LEWIJ 
S.  WARE,  C.  E.,  M.  E.  Illustrated  by  ninety  engravings.  8vo. 

$4.04 

WARN.— The  Sheet-Metal  Worker's  Instructor: 

For  Zinc,  Sheet-Iron,  Copper,  and  Tin- Plate  Workers,  etc.  Contain- 
ing a  selection  of  Geometrical  Problems ;  also,  Practical  and  Simple 
Rules  for  Describing  the  various  Patterns  required  in  the  different 
branches  of  the  above  Trades.  By  REUBEN  H.  WARN,  Practical 
Tin-Plate  Worker.  To  which  is  added  an  Appendix,  containing 
Instructions  for  Boiler-Making,  Mensuration  of  Surfaces  and  Solids, 
Rules  for  Calculating  the  Weights  of  different  Figures  of  Iron  and 
Steel,  Tables  of  the  Weights  of  Iron,  Steel,  etc.  Illustrated  by  thirty- 
two  Plates  and  thirty-seven  Wood  Engravings.  8vo.  .  $3.00 

WARNER.— New  Theorems,  Tables,  and  Diagrams,  for  the 

Computation  of  Earth-work : 

Designed  for  the  use  of  Engineers  in  Preliminary  and  Final  Estimates 
of  Students  in  Engineering,  and  of  Contractors  and  other  non-profes. 
sional  Computers.  In  two  pajrts,  with  an  Appendix.  Part  I.  A  Prac- 
tical Treatise;  Part  II.  A  Theoretical  Treatise,  and  the  Appendix. 
Containing  Notes  to  the  Rules  and  Examples  of  Part  I. ;  Explana- 
tions of  the  Construction  of  Scales,  Tables,  and  Diagrams,  and  a 
Treatise  upon  Equivalent  Square  Bases  and  Equivalent  Level  Heights. 
The  whole  illustrated  by  numerous  original  engravings,  comprising 
explanatory  cuts  for  Definitions  and  Problems,  Stereometric  Scales 
and  Diagrams,  and  a  series  of  Lithographic  Drawings  from  Models  t 
Showing  all  the  Combinations  of  Solid  Forms  which  occur  in  Railroad 
Excavations  and  Embankments.  By  JOHN  WARNER,  A.  M.,  Mining 
and  Mechanical  Engineer.  Illustrated  by  14  Plates.  A  new,  revised 
and  improved  edition.  8vo $4.OC 

WATSON.— A  Manual  of  the  Hand-Lathe  : 

Comprising  Concise  Directions  for  Working  Metals  of  all  kinds, 
Ivory,  Bone  and  Precious  Woods;  Dyeing,  Coloring,  and  French 
Polishing;  Inlaying  by  Veneers,  and  various  methods  practised  to 
produce  Elaborate  work  with  Dispatch,  and  at  Small  Expense.  By 
EGBERT  P.  WATSON,  Author  of  "  The  Modern  Practice  of  American 
Machinists  and  Engineers."  Illustrated  by  78  engravings.  $1.50 

WATSON. — The  Modern  Practice  of  American  Machinists  and 

Engineers 

Including  the  Construction,  Application,  and  Use  of  Drills,  LatVio 
Tools,  Cutters  for  Boring  Cylinders,  and  Hollow-work  generally,  with 
the  most  Economical  Speed  for  the  same ;  the  Results  verified  bj 
Actual  Practice  at  the  Lathe,  the  Vise,  and  on  the  Floor.  Together 


HENRY  CAREY  BA1RD  &  CO.'S  CATALOGUE.  2q 

with  Workshop  Management,  Economy  of  Manufacture,  the  Steam 
Engine,  Boiltrs,  Gears,  Belling,  etc.,  etc.  By  EGBERT  P.  WATSON 
Illustrated  by  eighty-six  engravings.  I2mo.  .  .  .  $2.50 

WATSON.— The  theory  and  Practice  of  the  Art  of  Weaving 

by  Hand  and  Power  • 

With  Calculations  and  Tables  for  the  Use  of  those  connected  with  the 
Trade.  By  JOHN  WATSON,  Manufacturer  and  Practical  Machine* 
Maker.  Illustrated  by  large  Drawings  of  the  best  Power  Looms. 
8vo.  .  $6.00] 

WATT.— The  Art  of  Soap  Making: 

A  Practical  Hand-book  of  the  Manufacture  of  Hard  and  Soft  Soaps, 
Toilet  Soaps,  etc.,  including  many  New  Processes,  and  a  Chapter  on 
the  Recovery  of  Glycerine  from  Waste  Leys.  By  ALEXANDER 
WATT.  111.  i2mo. $3.00 

WE ATHERLY.— Treatise  on  the  Art  of  Boiling  Sugar,  Crys* 

tailizing,  Lozenge-making,  Comfits,  Gum  Goods, 
And  other  processes  for  Confectionery,  etc.,  in  which  are  explained. 
in  an  easy  and  familiar  manner,  the  various  Methods  of  Manufactur- 
ing every  Description  of  Raw  and  Refined  Sugar  Goods,  as  sold  bj 
Confectioners  and  others.     121110 $1-50 

WIGHT  WICK. —Hints  to  Young  Architects: 
Comprising  Advice  to  those  who,  while  yet  at  school,  are  destined 
to  the  Profession;  to  such  as,  having  passed  their  pupilage,  are  aboul 
to  travel ;  and  to  those  who,  having  completed  their  education,  are 
about  to  practise.  Together  with  a  Model  Specification  involvirg  a 
great  variety  of  instructive  and  suggestive  matter.  By  GEORGE 
WIGHTWICK,  Architect.  A  new  edition,  revised  and  considerably 
enlarged ;  comprising  Treatises  on  the  Principles  of  Constructions 
and  Design.  By  G.  HUSKISSON  GUILLAUME,  Architect.  Numerous 
illustrations.  One  vol.  I2mo.  ......  #2.00 

WILL. — Tables  of  Qualitative  Chemical  Analysis. 

With  an  Introductory  Chapter  on  the  Course  of  Analysis.  By  Pro 
essor  HEINRICH  WILL,  of  Giessen,  Germany.  Third  American, 
from  the  eleventh  German  edition.  Edited  by  CHARLES  F.  HlMES 
Ph.  D.,  Professor  of  Natural  Science,  Dickinson  College,  Carlisle,  Pa 
8vo.  .  $i-Sr; 

WILLIAMS.— On  Heat  and  Steam  : 

Embracing  New  Views  of  Vaporization,  Condensation,  and  Explo- 
sion. By  CHARLES  WYE  WILLIAMS,  A.  I.  C.  E.  Illustrated  Svo. 

$2.50 

WILSON. — A  Treatise  on  Steam  Boilers  : 

Their  Strength,  Construction,  and  Economical  Working.  By  ROBER! 
WILSON.  Illustrated  I2mo $2.50 

WILSON. — First  Principles  of  Political  Economy: 

With  Reference  to  Statesmanship  and  the  Progress  of  Civilization. 
Ry  Professor  W.  D.  WILSON,  of  the  Cornell  University.  A  new  and 
revised  edition.  121110.  .  .  .  .  .  .  .  $1.50 


30        HENRY   CAREY   BAIRD   &   CO.'S  CATALOGUE. 


WOHLER.— A  Hand-Bookof  Mineral  Analysis: 

By  F.  WoHLER,  Professor  of  Chemistry  in  the  University  of  Gottin- 
gen.  Edited  by  HENRY  B.  NASON,  Professor  of  Chemistry  in  the 
Renssalaer  Polytechnic  Institute,  Troy,  New  York.  Illustrated. 
I2mo $2.50 

WORSSAM. — On  Mechanical  Saws  : 

From  the  Transactions  of  the  Society  of  Engineers,  1869.  By  S.  W. 
WORSSAM,  JR.  Illustrated  by  eighteen  large  plates.  8vo.  $2.50 


RECENT   ADDITIONS. 

BRANNT. — Varnishes,  Lacquers,  Printing  Inks  and  Sealing - 
Waxes : 

Their  Raw  Materials  and  their  Manufacture,  to  which  is  added  the 
Art  of  Varnishing  and  Lacquering,  including  the  Preparation  of  Put- 
ties and  of  Stains  for  Wood,  Ivory,  Bone,  Horn,  and  Leather.  By 
WILLIAM  T.  BRANNT.  Illustrated  by  39  Engravings,  338  pages. 

I2mo $3-0° 

BRANNT — The  Practical  Scourer  and  Garment  Dyer: 

Comprising  Dry  or  Chemical  Cleaning ;  the  Art  of  Removing  Stains  -f 
Fine  Washing;  Bleaching  and  Dyeing  of  Straw  Hats,  Gloves,  and 
Feathers  of  all  kinds;  Dyeing  of  Worn  Clothes  of  all  fabrics,  in- 
cluding Mixed  Goods,  by  One  Dip;  and  the  Manufacture  of  Soaps 
and  Fluids  for  Cleansing  Purposes.  Edited  by  WILLIAM  T.  BRANNT, 
Editor  of  "The  Techno-Chemical  Receipt  Book."  Illustrated. 
203  pages.  I2mo. .  $2.00 

BRANNT.— Petroleum . 

Its  History,  Origin,  Occurrence,  Production,  Physical  and  Chemical 
Constitution,  Technology,  Examination  and  Uses ;  Together  with 
the  Occurrence  and  Uses  of  Natural  Gas.  Edited  chiefly  from  the 
German  of  Prof.  Hans  Hoefer  and  Dr.  Alexander  Veith,  by  WM. 
T.  BRANNT.  Illustrated  by  3  Plates  and  284  Engravings.  743  pp. 
8vo.  £7.50 

BRANNT. — A  Practical  Treatise  on  the  Manufacture  of  Vine- 
gar and  Acetates,  Cider,  and  Fruit- Wines  : 
Preservation  of  Fruits  and  Vegetables  by  Canning  and  Evaporation ; 
Preparation  of  Fruit-Butters,  Jellies,  Marmalades,  Catchups,  Pickles, 
Mustards,  etc.  Edited  from  various  sources.  By  WILLIAM  T. 
BRANNT.  Illustrated  by  79  Engravings.  479  pp.  8vo.  $5.00 

BRANNT.— The  Metal  Worker's    Handy-Book   of  Receipts 

and  Processes : 

Being  a  Collection  of  Chemical  Formulas  and  Practical  Manipula- 
tions for  the  working  of  all  Metals ;  including  the  Decoration  and 
Beautifying  of  Articles  Manufactured  therefrom,  as  well  as  their 
Preservation.  Edited  from  various  sources.  By  WILLIAM  T. 
BRANNT.  Illustrated.  I2mo.  $2.50 


HENRY  CAREY  BA1RD   &  CO.'S  CATALOGUE.       3r 

DEITE.— A  Practical  Treatise   on   the  Manufacture  cf  Per* 

fumery : 

Comprising  directions  for'  making  all  kinds  of  Perfumes,  Sachet 
Powders,  Fumigating  Materials,  Dentifrices,  Cosmetics,  etc.,  with  a 
full  account  of  the  Volatile  Oils,  Balsams,  Resins,  and  other  Natural 
and  Artificial  Perfume-substances,^  including  the  Manufacture  of 
Fruit  Ethers,  and  tests  of  their  purity.  By  Dr.  C.  DEITE,  assisted 
by  L.  BORCHERT,  F.  EICHBAUM,  E.  KUGLER,  H.  TOEFFNER,  and 
other  experts.  From  the  German,  by  WM.  T.  BRANNT.  28  Engrav- 
ings. 358  pages.  8vo. $3.00 

EDWARDS. — American    Marine   Engineer,    Theoretical   and 

Practical : 

\Vith  Examples  of  the  latest  and  most  approved  American  Practice. 
By  EMORY  EDWARDS.  85  illustrations.  I2mo.  .  .  $2.50 

EDWARDS. — 900    Examination   Questions  and   Answers: 
For  Engineers  and  Firemen  (Land  and  Marine)  who  desire  to  ob- 
tain a  United   States  Government  or  State  License.     Pocket-book 
form,  gilt  edge          ........        $1.5° 

POSSELT.— Technology  of  Textile  Design  : 

Being  a  Practical  Treatise  on  the  Construction  and  Application  of 
Weaves  for  all  Textile  Fabrics,  with  minute  reference  to  the  latest 
Inventions  for  Weaving.  Containing  also  an  Appendix,  showing 
the  Analysis  and  giving  the  Calculations  necessary  for  the  Manufac« 
tine  of  the  various  Textile  Fabrics.  By  E.  A.  POSSELT,  Head 
Master  Textile  Department,  Pennsylvania  Museum  and  School  of 
Industrial  Art,  Philadelphia,  with  over  1000  illustrations.  293 
pages.  4to $5-°° 

POSSELT. — The  Jacquard  Machine  Analysed  and  Explained : 
With  an  Appendix  on  the  Preparation  of  Jacquard  Cards,  and 
Practical  Hints  to  Learners  of  Jacquard  Designing.  By  E.  A. 
POSSELT.  With  230  illustrations  and  numerous  diagrams.  127  pp. 
4to $3.00 

POSSELT.— The  Structure  of  Fibres,  Yarns  and  Fabrics: 
Being  a  Practical  Treatise  for  the  Use  of  all  Persons  Employed  in 
the  Manufacture  of  Textile  Fabrics,  "Containing  a  Description  of  the 
Growth  and  Manipulation  of  Cotton,  Wool,  Worsted,  Silk  Flax, 
Jute,  Ramie,  China  Grass  and  Hemp,  and  Dealing  with  all  Manu- 
facturers' Calculations  for  Every  Class  of  Material,  also  Giving 
Minute  Details  for  the  Structure  of  all  kinds  of  Textile  Fabrics,  and 
an  Appendix  of  Arithmetic,  specially  adapted  for  Textile  Purposes. 
By  E.  A.  POSSELT.  Over  400  Illustrations,  quarto.  .  $10.00 

RICH. — Artistic  Horse-Shoeing: 

A  Practical  and  Scientific  Treatise,  giving  Improved  Methods  of 
Shoeing,  with  Special  Directions  for  Shaping  Shoes  to  Cure  Different 
Diseases  of  the  Foot,  and  for  the  Correction  of  Faulty  Action  in 
Trotters.  By  GEORGE  E.  RICH.  62  Illustrations.  153  pages. 
.  I2mo $1.00 


32       HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 

RICH ARDSON.— Practical  Blacksmithing : 

A  Collection  of  Articles  Contributed  at  Different  Times  by  Skilled 
Workmen  to  the  columns  of  "  The  Blacksmith  and  Wheelwright," 
and  Covering  nearly  the  Whole  Range  of  Black-smithing,  from  the 
Simplest  Job  of  Work  to  some  of  the  Most  Complex  Forgings. 
Compiled  and  Edited  by  M.  T.. RICH  ARDSON. 

Vol.1.  210  Illustrations.  224  pages.  I2mo.  .  .  $1.00 
Vol.  II.  230  Illustrations.  262  pages.  I2mo.  .  .  $1.00 
Vol.  III.  390  Illustrations.  307  pages.  I2mo.  .  ,  $1.00 
Vol.  IV.  226  Illustrations.  276  pages.  I2mo.  ,  .  $1.00 

RICHARDSON.— The  Practical  Horseshoer: 

Being  a  Collection  of  Articles  on  Horseshoeing  in  all  its  Branche* 
which  have  appeared  from  time  to  time  in  the  columns  of  "  1  he 
Blacksmith  and  Wheelwright,"  etc.  Compiled  and  edited  by  M.  T. 
RICHARDSON.  174  illustrations $1.00 

ROPER. — Instructions    and   Suggestions   for   Engineers   and 

Firemen : 
By  STEPHEN  ROPER,  Engineer.     i8mo.     Morocco        .        $2.00 

ROPER.— The  Steam  Boiler:  Its  Care  and  Management: 
By  STEPHEN  ROPER,  Engineer.     I2mo.,  tuck,  gilt  edges.        $2.00 

ROPER. — The  Young  Engineer's  Own  Book: 

Containing  an  Explanation  of  the  Principle  and  Theories  on  which 
the  Steam  Engine  as  a  Prime  Mover  is  Based.  By  STEPHEN  ROPER, 
Engineer.  160  illustrations,  363  pages.  i8mo.,  tuck  .  £3.00 

ROSE. — Modern  Steam -Engines: 

An  Elementary  Treatise  upon  the  Steam-Engine,  written  in  Plain 
language ;  for  Use  in  the  Workshop  as  well  as  in  the  Drawing  Office. 
Giving  Full  Explanations  of  the  Construction  of  Modern  Steanv 
Engines  :  Including  Diagrams  showing  their  Actual  operation.  To- 
gether with  Complete  but  Simple  Explanations  of  the  operations  of 
Various  Kinds  of  Valves,  Valve  Motions,  and  Link  Motions,  etc., 
thereby  Enabling  the  Ordinary  Engineer  to  clearly  Understand  the 
Principles  Involved  in  their  Construction  and  Use,  and  to  Plot  out 
their  Movements  upon  the  Drawing  Board.  By  JOSHUA  ROSE.  M.  E. 
Illustrated  by  422  engravings.  Revised.  358  pp.  .  .  $6.00 

ROSE.— Steam  Boilers: 

.A  Practical  Treatise  on  Boiler  Construction  and  Examination,  for  the 
Use  of  Practical  Boiler  Makers,  Boiler  Users,  and  Inspectors;  and 
embracing  in  plain  figures  all  the  calculations  necessary  in  Designing 
or  Classifying  Steam  Boilers.  By  JOSHUA  ROSE,  M.  E.  Illustrated 
by  73  engravings.  250  pages.  8vo $2.  "jo 

SCHRIBER— The  Complete  Carriage  and  Wagon  Painter: 
A  Concise  Compendium  of  the  Art  of  Painting  Carriages,  Wagons, 
and  Sleighs,  embracing  Full  Directions  in  all  the  Various  Branches, 
including  Lettering,  Scrolling,  Ornamenting,  Striping,  Varnishing, 
and  Coloring,  with  numerous  Recipes  for  Mixing  Color*.  73  Illus- 
trations. 177  pp.  I2mo $l.QQ 


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